SYN flood attack: Origin and Basics

In the 1990s, a man named Wietse Venema explained a certain attack method in-depth. On its surface, the concept seems innocuous enough. In a network protocol, namely TCP, a three-way handshake commences communication. Imagine this as a modern chivalry ritual between your computer and the server you want to engage with.

1. You send a SYN (synchronize) packet: “Hi, can we chat?“
2. Server sends back SYN-ACK (acknowledgment): “Sure, let’s talk.“
3. You finish with an ACK: “Cool, let’s get started.“

What SYN flood attack is?

Broadly speaking, a SYN flood attack, also referred to as a TCP/IP-based attack, is a type of Denial of Service (DDoS) attack on a system. It might be compared to an irritating prankster continuously dialing a business phone to keep the line busy and prevent legitimate callers from reaching the establishment. The attacker here sends a flood of SYN requests from either a single or multiple spoofed IP addresses to a server with the malicious intent to halt the server’s functionality to process new incoming service requests. As the server gets trapped in a vicious cycle of responding to these inexistent or half-open connections, it can lead to crashing or becoming unavailable to legitimate users.

How does it work? 

The mechanics of a SYN flood operate in a methodical sequence of steps that exploit the TCP handshake protocol. Let’s break it down for clarity:

Step 1: Identifying the Target

The attacker first picks out the target server. Usually, they’re gunning for a specific service, like a website or an application hosted on that server.

Step 2: Initiating SYN Requests

Here, the attacker commences the mischief by generating a multitude of SYN packets. Each of these SYN packets asks the server, in essence, for permission to establish a connection.

Step 3: Half-Open Connections

Upon receiving a SYN request, the server reciprocates with a SYN-ACK packet and moves the corresponding request to a backlog queue. This places the connection in a “half-open” state, awaiting the client’s final ACK for completion.

Step 4: Server Response

At this juncture, the attacker ghosts the server, never sending the final ACK to complete the handshake. Consequently, the server’s backlog queue starts brimming with incomplete handshakes.

Step 5: Resource Exhaustion

With each half-open connection, the server allocates a chunk of its resources. As these incomplete connections accrue, the server begins to hit its limit on resources.

Step 6: Denial of Service

At this point, the server becomes unable to accept any new connections. Legitimate users trying to connect encounter timeouts or failures, achieving the attacker’s endgame of denying service.

Types of SYN Flood Attacks

SYN flood attacks can take on multiple forms, each with its own level of complexity and associated risks:

1. Direct Attack: In this type of attack, the attacker does not hide their IP address, meaning that all traffic comes from a single source. This makes it relatively easier for network administrators to identify and block the attack by filtering the IP address. However, direct attacks can still overwhelm a server, especially if they come from high-capacity sources.
2. Spoofed Attack: Here, the attacker sends SYN requests using spoofed IP addresses, making it difficult to track the origin of the traffic. The server tries to send SYN-ACK packets to non-existent or unreachable IPs, leaving the connections open and slowly exhausting server resources​. Spoofing adds an extra layer of complexity, making it harder to mitigate, as simply blocking the traffic source won’t solve the problem.
3. Distributed Attack (DDoS): In a distributed SYN flood attack, the attacker uses a botnet – a network of compromised devices – to send SYN requests from various IP addresses. This creates massive amounts of traffic from multiple sources, overwhelming the server and making it extremely difficult to pinpoint and block the attack. This method was infamously used by the Mirai botnet, which leveraged IoT devices to launch one of the largest DDoS attacks in history​.

Ways to mitigate the SYN flood attack

Ah, but there’s hope! Multiple strategies can serve as lifelines in mitigating the fallout from a SYN flood.

SYN cookies

Implementing SYN cookies proves useful in minimizing risk. When deployed, the server doesn’t allocate resources right away for a new SYN request. Rather, it converts the connection into a unique cryptographic cookie. Only when the handshake gets completed does the server expend resources, reducing vulnerability to attacks.

Rate limiting

Another solid tactic involves imposing rate limiting on incoming SYN packets. By setting a strict threshold for the number of allowable new connections per unit of time, the server can effectively nip malicious flood attempts in the bud.

DDoS Protection

Incorporating DDoS protection is an advanced, indispensable strategy. These specialized solutions not only defend against SYN flood attacks but also guard against a broader range of DDoS threats. DDoS protection services usually feature large traffic scrubbing networks that can sift through immense volumes of data, allowing legitimate traffic through while blocking malicious requests.

Anycast DNS

Anycast DNS serves as another invaluable layer of defense. By distributing incoming traffic across multiple data centers (PoPs), it minimizes the load on any single server. This distribution can effectively dilute a SYN flood attack, rendering it far less potent. Anycast DNS is especially beneficial when used in conjunction with DDoS protection services, providing an additional layer of robust, scalable defense.

Robust Load balancers
High-capacity load balancers can significantly improve your system’s capacity to manage an enormous volume of connection requests. In turn, this can enhance your network’s ability to resist SYN flood attacks.

Monitoring services
Real-time Monitoring services track and scrutinize network patterns, activities, and performance, enabling the early detection of potential threats or attacks. These services can monitor server health, network performance, and traffic patterns, thereby identifying and alerting about possible anomalies that might indicate a SYN flood attack.

Firewall rules

Tweaking firewall configurations can also be invaluable. For instance, you can set rules to block incoming requests from a specific IP address if it exceeds a set number of SYN requests within a short timeframe.

Suggested article: Router vs firewall

Consequences of non-protection

• Service disruption: SYN flood attacks can result in service disruption or downtime, as the targeted server becomes overwhelmed and unable to handle legitimate requests.
• Financial loss: Downtime can lead to financial losses for businesses, especially e-commerce websites, online services, and organizations heavily reliant on internet connectivity.
• Reputation damage: Frequent DDoS attacks, including SYN floods, can tarnish a company’s reputation, eroding trust and customer confidence.
• Security overhaul costs: Post-attack, merely patching vulnerabilities won’t suffice. A complete revamp of security protocols becomes vital, often draining both time and financial resources.

Conclusion

In a world increasingly reliant on digital technology, understanding and defending against threats like SYN flood attacks is crucial. While they are a potent threat, solutions such as SYN cookies and robust load balancers offer effective means of mitigation. In essence, maintaining cybersecurity is not just a good idea, but a necessity in today’s digital landscape.

The post Understanding SYN flood attack appeared first on ClouDNS Blog.

Botnet – What does it mean?

A Botnet is a network of different devices, like computers, smartphones, tablets, and IoT, which are infected with malware and controlled by a cyber-criminal, also known as a bot herder. Each individual device within the botnet network is also known as a bot or zombie.

These hijacked devices are utilized to carry out different scams and cyberattacks, like sending spam emails, distributing malware, and preparing DDoS attacks. The assembly of a botnet is usually the infiltration step of a multi-layer scheme. Botnets employ the devices of regular users for scams and disruptions without requiring the permission of the owner.

DDoS Protected DNS Service

You are probably wondering what the botnet attack actually is and how it works. So, let’s expand the topic and clarify for what purposes they are used!

What are botnets used for?

There are different reasons why attackers use botnets. However, the most popular intentions are related to stealing data and money. Here are some of the most common usages of the networks of hijacked devices:

Fraudulent or money stealing

Cybercriminals can perform attacks that involve a botnet network for stealing money directly or indirectly. Some of the popular methods to achieve that are phishing emails or making a fake website that looks exactly like the original bank website, for example. Then, they are able to translate the payment or transaction details and utilize them to steal money.

Data theft

The data of the users is highly valued in the market. Cybercriminals are well aware of that. Therefore, they use botnets for stealing individual personal information, or even more, they break into the database of a precise company. The next step for them is to sell the user information to third parties and make a profit from it. These botnets could stay inactive and only steal personal details.

Perform spamming and phishing frauds

By implementing botnets, attackers can execute large email spamming and phishing scams. That is because they can spread malicious emails to numerous targets easily. Moreover, there are spam botnets that are precisely designed for such tasks.

However, the intentions are always the same, meaning stealing money or information, even if the methods differ. Yet, there are a specific group of cybercriminals who use botnets only because they can. They only aim to show their abilities and demonstrate their superiority to the rest of the world. There are different examples of security breaches where the attackers steal personal details and reveal them on the dark web for free.

Botnet attack – explained in detail

We talk about a Botnet attack when cybercriminals inject malware into the network to control them as a collective used for initiating cyberattacks. Otherwise, botnets themselves are simply a network of devices. 

The scale of a Botnet attack could be pretty large, and any device could fall victim to it. So, cybercriminals use additional machinery or devices to support and improve the mastership of a botnet.

Bot herder is needed to guide and control the group of hijacked devices in the network. The attacker uses it via remote commands to guide the devices and make them complete specific actions.

Bot or zombie computer is an infected device (system) used to create a botnet. The bots are guided by the bot herder’s command, and they behave by its instructions.

Let’s break down the construction process of a Botnet attack. Here are 3 main steps you should know:

Step 1: Prep and Expose

The cybercriminal discovers a vulnerability to introduce into the user’s device. The process of searching for a vulnerability involves the website, human behavior, and application. That way, the attacker prepares a set-up to drown the victim to get exposed to malware without notice. Typically, the vulnerabilities are found in websites and software, and the malware is delivered through emails or messages.

‍Step 2: Infecting the user

The attacker activates the malware, and the user’s device is infected and has compromised security. Typically, for that purpose, cybercriminals use the social engineering method or the Trojan virus. Another more aggressive approach includes deploying drive-by-download strategies to infect the device. However, with all of these methods, cybercriminals aim to weaken the target with botnet malware.

‍Step 3: Taking control over the targeted devices

The last step is taking control of each infected device. All of them are systematized, and the attacker involves a method for managing them remotely. Numerous devices are under control through a massive zombie network. After completing this step, the cybercriminal gains admin-like access to the targeted devices. Moreover, it has the ability to read and change the stored information, capture it, share it, or watch all of the activities on the device.

Most popular Botnet attack types

Botnets are attacks by themselves also, but they are a perfect instrument for performing secondary frauds and cybercrimes on a giant scale. Here are the most popular Botnet attack types:

DDoS attack

DDoS attacks aim to overwhelm a target server, network, or device with massive traffic. The zombie devices (bots) send large amounts of requests aiming to crash or at least slow down the target significantly.

That is one of the most popular forms of using botnets for criminal purposes. Additionally, it is commonly the one that is the most dangerous. The negative effects of DDoS attacks are often long-term and severe. That includes not only financial losses but also reputational damages for the target organization.

That is critical for everyone that has a functional website and especially for businesses that operate and offer their services online. So for sure, proper DDoS protection is a must! Unfortunately, it is already too late for you to plan your response when a DDoS attack appears. Therefore, protection and mitigation should be planned.

Phishing

Botnet attacks are commonly built by phishing tactics. That way, they infect more devices and extend the size of the botnet.

Additionally, phishing and other methods of social engineering attacks include a botnet that sends emails, posts comments or sends messages on social media acting like people or businesses that the victim trusts, commonly used to steal your banking details.

Precisely phishing is hard to defend against because humans easily fall victim to them.

Brute Force attack

Another popular way that bot headers use botnets is to complete different Account Takeover (ATO) attacks, mostly Brute Force attacks (credential cracking).

For a Brute Force attack, the zombie devices are instructed to test the various options of a user password and “crack” it. For instance, if there is a PIN with 4 digits, bot device 1 is going to test “0000”, the second bot device is going to test “0001”, etc. That continues until one of them guesses the correct PIN.

Defending against this botnet attack is also very challenging. It is effective in exploiting weak user credentials.

Which devices can become targets of a Botnet?

Devices infected with malware, also known as “bots” or “zombies,” can be remotely controlled by attackers. Almost any device with an internet connection can potentially become a target for a botnet if it has vulnerabilities that can be exploited. Here are some common types of devices that can be targeted:

• Personal Computers: Desktops and laptops running various operating systems, including Windows, macOS, and Linux, can be targeted by botnets if they have security vulnerabilities. Malware can infect these devices through malicious downloads, email attachments, or drive-by downloads.
• Servers: Web servers, email servers, and other types of servers are attractive targets for botnets because they often have high-speed internet connections and large resources. Compromised servers can be used to host malicious content, launch DDoS attacks, or distribute malware.
• Mobile Devices: Smartphones and tablets are also exposed to botnet infections. Malicious apps, compromised app stores, and phishing attacks can be used to target these devices. Both Android and iOS can be affected by botnet-related threats.
• IoT Devices: Internet of Things devices, such as smart cameras, smart thermostats, routers, and smart appliances, are targeted by botnets. They are often less protected and may have default or weak passwords, making them easy targets for exploitation.
• Network Equipment: Routers, switches, and other devices can be compromised by botnets. Once infected, these devices can be used to control network traffic, redirect users to malicious websites, or participate in DDoS attacks.

Signs your device could be part of a Botnet

Here are the most common signals that your device could be part of a Botnet:

• Unusual Sluggishness: If your device suddenly becomes slow or unresponsive, it may be because a botnet is using its resources.
• Excessive Data Usage: A sudden spike in data usage without an apparent reason could indicate your device is participating in botnet activities.
• Unwanted Pop-ups: Frequent pop-up ads or redirects to suspicious websites may signal that your device is under the control of a botmaster.
• High CPU Usage: Constantly high CPU usage, even when you’re not running intensive applications, can indicate malicious activity.
• Outbound Spam Emails: If your email contacts receive spam from your account without your knowledge, your device may send spam as part of a phishing attack.
• Disabled Security Software: Malware in a botnet often tries to disable antivirus and firewall protection to avoid detection.
• Unexplained Software Installs: Unauthorized software installations or changes to your device’s settings can be a sign that attackers may have control over it.
• Strange Network Activity: Monitor your network traffic for unusual patterns, such as frequent connections to unfamiliar IP addresses or domains.

How to protect yourself?

Here are some things you can do to protect yourself from botnet malware.

• Strong passwords. Make sure all of your smart devices have complex long passwords. That will keep them safer compared to a short and weak password, like “123456”.
• Update your OS. You should update your software. That way, you are receiving all of the security patches that can deal with familiar vulnerabilities.
• Change admin settings and passwords across all of your devices. Make sure to check all potential privacy and security options. That includes everything that connects device-to-device or to the Internet. If you skip changing to custom login credentials and private connectivity, cybercriminals will be capable of breaching and infecting all of your devices.
• Avoid opening suspicious email attachments. Before you download a file, make sure to verify the sender’s email address.
• Avoid clicking on links in messages. Different texts, emails, or social media messages could include malware. Moreover, by doing so, you can avoid drive-by downloads and DNS cache poisoning.
• Reliable antivirus software. It is going to help you improve your security and keep yourself protected from Trojans and other threats.

Impact of Botnets on Businesses

Botnets are a growing threat to businesses of all sizes, exploiting weak spots in networks to carry out malicious activities. Here’s a breakdown of how they can impact your business:

• Financial Losses

Botnets can cause serious financial damage. They might steal sensitive data directly, demand ransoms after launching ransomware attacks, or disrupt your services, leading to lost revenue. For example, a Distributed Denial of Service (DDoS) attack could take down your website, resulting in significant downtime and a drop in productivity.

• Damage to Your Reputation

The impact of a botnet attack goes beyond immediate financial losses. It can also severely damage your company’s reputation. Customers and partners may lose trust in a business’s ability to protect confidential information, resulting in long-term loss of clientele. There could also be legal consequences if your company fails to comply with data protection laws. Recovering from such an attack often requires significant investment in cybersecurity measures, system restorations, and efforts to rebuild public trust.

• Increased Operational Costs

Botnet infections can also lead to the unauthorized use of company resources, increasing operational costs and exposing internal systems to even more security risks. Small and medium-sized businesses are especially vulnerable, as they might not have the necessary infrastructure or expertise needed to effectively defend against these threats.

To reduce the risk of botnet attacks, it’s essential to adopt proactive security measures and include regular employee training, robust incident response plans, and a strong focus on cybersecurity. By taking these steps, you can help protect your business from the negative effects of these attacks.

Some famous Botnet attacks

Mirai – 2016

The massive Mirai botnet attack was initiated through a DDoS attack, and it made the Internet unavailable in the U.S. It was the first major botnet that infected insecure IoT devices. At the peak of the attack, it got to over 600,000 infected devices. 

3ve – 2018

3ve, pronounced Eve, started as a small botnet. Yet, the number of infected devices reached a tremendous 1.7 million. The botnet managed to falsify billions of ad views. As a result, businesses paid millions for ads that no real human, a regular internet user, ever saw.

Conclusion

Botnet and Botnet attacks are cyber threats that should not be neglected! It is important to keep yourself or your organization safe from such malicious attempts. Otherwise, they could lead to large financial and reputational damages!

The post Botnet – what is it, and how does a Botnet attack work? appeared first on ClouDNS Blog.

SMTP Explanation

SMTP, or Simple Mail Transfer Protocol, is the standard protocol used for sending emails across the Internet. It operates on a client-server model, where the sender’s email client communicates with the email server to transmit the message to the recipient’s email server, which then delivers it to the recipient’s inbox.

SMTP is a text-based protocol and operates over TCP/IP, typically using port 25. While SMTP is robust and has been the backbone of email communication for decades, it was not originally designed with security in mind. Over time, enhancements like SMTP over SSL/TLS have been introduced to secure email transmission, but the protocol’s openness still leaves it vulnerable to various attacks.

Suggested: SSL/TLS monitoring explained in details

What is SMTP Smuggling?

SMTP Smuggling is a sophisticated attack technique that exploits the way email servers handle SMTP traffic. Specifically, it targets the discrepancies in how different email servers and security gateways interpret SMTP commands and email headers.

In essence, SMTP Smuggling involves crafting email messages that appear legitimate to some servers but are interpreted differently by others, enabling attackers to bypass security filters, deliver malicious content, or even exfiltrate data. This attack vector can be particularly dangerous because it can evade traditional security mechanisms designed to inspect and filter email traffic.

Key Components 

• Header Injection and Manipulation: SMTP Smuggling often involves injecting additional SMTP headers or manipulating existing ones to deceive downstream email servers. For example, an attacker might craft an email with two “Content-Length” headers, each with a different value. Some servers might use the first header, while others might use the second, leading to different interpretations of where the email body starts and ends.
• Multi-Stage Parsing Differences: Different email servers and security appliances may parse SMTP traffic differently. Attackers exploit these parsing discrepancies to create situations where one server interprets a part of the message as legitimate while another interprets it as malicious. For example, an email could be crafted to appear benign to a security gateway but malicious to the final mail server.
• Boundary Mismatch Attacks: These involve crafting email messages that confuse the boundary definitions between headers and the body, or between different parts of a MIME (Multipurpose Internet Mail Extensions) email. This mismatch can cause email security solutions to misinterpret the boundaries, allowing malicious content to slip through.

How does SMTP Smuggling work?

SMTP Smuggling typically follows these steps:

1. Crafting the Email: The attacker crafts an email with specific SMTP headers and commands that exploit the differences in how email servers and security gateways interpret SMTP traffic. This may involve splitting the email into parts that are handled differently by each server in the relay chain.
2. Sending the Email: The malicious email is sent through a series of relay servers. The attacker’s goal is to have the email appear benign to the initial security gateway but to have its true malicious nature revealed once it reaches a later point in the relay chain.
3. Exploiting Inconsistencies: As the email traverses through different servers, some may interpret the crafted commands differently. For example, one server might treat a part of the email as a legitimate command, while another might ignore it, allowing the attacker to introduce malicious content or bypass security controls.
4. Bypassing Security: The email eventually reaches the target server or inbox, where its malicious payload can be executed. Because the attack exploited inconsistencies in server interpretations, traditional security measures may have been bypassed, leaving the target vulnerable.

Detection and Mitigation Strategies

Given the covert nature of SMTP smuggling, detecting it can be challenging. However, there are steps that organizations can take to mitigate the risk:

• Use Advanced Email Security Solutions: Implement advanced email security solutions that go beyond traditional spam filters. These solutions should include deep content inspection, behavioral analysis, and machine learning to detect and block sophisticated threats like SMTP smuggling.
• Regularly Update and Patch Email Servers: Ensure that your email servers and associated software are regularly updated and patched. Many SMTP smuggling attacks exploit vulnerabilities in outdated software, so keeping your systems current is critical.
• Monitor Email Traffic: Implement monitoring tools to analyze email traffic patterns. Anomalies in SMTP communication, such as unusual command sequences or unexpected payloads, can be indicators of smuggling attempts.

Suggested: What is SMTP Monitoring?

• Educate Users: Train employees to recognize phishing attempts and other suspicious emails. While SMTP smuggling can bypass technical defences, a vigilant and well-informed workforce can serve as a strong line of defence.
• Implement DMARC, SPF, and DKIM: Domain-based Message Authentication, Reporting, and Conformance (DMARC), Sender Policy Framework (SPF), and DomainKeys Identified Mail (DKIM) are protocols that help authenticate email senders. Properly configuring these protocols can reduce the risk of email spoofing and smuggling.
• Perform Regular Security Audits: Conduct regular security audits of your email infrastructure to identify potential vulnerabilities and weaknesses. This proactive approach can help you address issues before they are exploited by attackers.

Conclusion

SMTP smuggling is a sophisticated and potentially devastating attack vector that targets the core of email communication. As cybercriminals continue to evolve their tactics, it is crucial for organizations to stay ahead of the curve by implementing robust email security measures and educating their employees about the dangers of these attacks. By understanding how SMTP smuggling works and taking proactive steps to protect your email systems, you can significantly reduce the risk of falling victim to this hidden threat.

The post What is SMTP Smuggling? How to detect and prevent it? appeared first on ClouDNS Blog.

Cybercriminals are using malicious domain names and DNS servers to bypass the protection and complete data exfiltration.

Before we jump into explaining what the DNS tunneling attack is and how it works, let’s talk a little bit more about what DNS is.

Domain Name System – explained

The Domain Name System, or just for short DNS, is a global naming database. Thanks to it, we are able to use the Internet, as we do in the present day. Its purpose is to translate human-readable domain names, such as example.net, into their corresponding machine-friendly IP addresses, such as 123.45.67.89. That way, regular users are not required to remember long and difficult numbers. Instead, people are easily memorizing domain names, and they can use them to reach and explore their favorite news, sports, or another website.

A lot of services rely on the large number of DNS translation queries that appear constantly. For that reason, DNS traffic is widely used and trusted. Due to the fact that DNS was not invented to transfer data packets but only for name resolution was not viewed as a threat to malicious communications and data exfiltration. Yet, DNS is not just a translation instrument for domain names. DNS queries can also transfer tiny portions of data between two devices, systems, and servers. The bad news is that this makes DNS a potential vector for attacks.

Unfortunately, the majority of organizations do not analyze the DNS packets for malicious activity frequently. Instead, they mainly concentrate on analyzing web or email traffic where they consider a possible attack could appear. The truth is that each endpoint should be under detailed monitoring for preventing DNS tunneling attacks.

DNS Tunneling – what do you have to know?

DNS Tunneling attack is a very popular cyber threat because it is very difficult to detect. It is used to route the DNS requests to a server controlled by the attacker and provides them with a covert command and control channel and data exfiltration path.

Typically, DNS tunneling involves data payloads that are added to the target DNS server. Additionally, they are implemented for gaining control of a remote server and applications. Moreover, for the purpose of this attack, the compromised system should be connected to an external network to achieve access to an internal DNS server with network access. Cybercriminals control a server that operates as an authoritative server and a domain name to complete the server-side tunneling and data payload executable programs.

5 DNS Attacks Types that could affect you

DNS Tunneling History

DNS tunneling history is highly related to the evolution of cybersecurity threats. It appeared as a technique for bypassing network restrictions and avoiding detection. At first, it was used for legitimate purposes like bypassing restrictive networks or anonymous online activity. However, DNS tunneling slowly became popular among malicious actors as a secret communication channel for data exfiltration and command-and-control purposes. The first examples of this attack appeared in the early 2000s and were often associated with malware propagation. Over the years, the attackers become more sophisticated, and their techniques have evolved. That forced cybersecurity specialists to develop advanced monitoring and prevention mechanisms to protect against it.

How does it work?

DNS tunneling attack takes advantage of the DNS protocol and achieves tunneling malware or data through a client-server model. Let’s explain how this attack actually works.

It all starts when a user downloads malware or the cybercriminal manages to exploit a vulnerability of the compromised device to transfer a malicious payload. In most cases, the cybercriminal wants to keep a connection with the compromised device, meaning to have the opportunity to run commands on the target device or exfiltrate data. Therefore, the attacker can set a command-and-control (C2) connection. Such traffic should be able to pass via different network perimeter security measures, plus it should avoid detection until it crosses the target network. 

For that reason, DNS is a suitable option for setting up the tunnel. That is a common term in cybersecurity which stands for a protocol connection that carries a payload that includes data (commands) and passes through perimeter security measures. That way, the DNS tunneling attack manages to hide information within DNS queries and send them to a server controlled by the cybercriminal. The DNS traffic passes freely through perimeter security measures, such as firewalls. For the purpose of setting the DNS tunnel, the cybercriminal registers a domain name and configures an authoritative name server under their control. 

Then the malware or payload on the compromised device initiates a DNS query for a subdomain that defines an encoded communication. The Recursive DNS server (DNS resolver) obtains the DNS query and routes it to the attacker’s server. The server responds with malicious DNS data containing data (command) back to the compromised device. That way, the attack passes without triggering any security measures.

Let’s break the DNS Tunneling attack into the following steps:

1. The cybercriminal registers a domain and points it to the server under its control. There is installed tunneling malware software. 
2. The cybercriminal infects a device with malware, penetrating the victim’s firewall. DNS requests don’t have restrictions for passing in and out of the firewall.
3. The Recursive DNS server (DNS resolver) requests the IP address through root and top-level domain servers.
4. Then the DNS resolver routes the DNS query back to the authoritative DNS server, which is controlled by the attacker and contains the tunneling software. 
5. The connection between the cybercriminal and the target is created without any notice.

Why do Attackers Use DNS Tunneling?

Attackers use DNS tunneling to exploit the widespread and often under-monitored nature of DNS traffic. This attack allows them to secretly transmit data between a compromised system and a command-and-control server. Since DNS queries and responses are generally trusted and rarely scrutinized, this technique can easily bypass firewalls and other security measures. DNS tunneling allows attackers to maintain persistent access, execute remote commands, and exfiltrate sensitive data without detection. The global reach and minimal inspection of DNS make it an ideal medium for hidden communication and data transfer.

Detecting DNS Tunneling

There are several techniques that can help you detect a DNS tunneling attack. However, we can distinguish them into two main categories – payload analysis and traffic analysis.

Payload analysis – The DNS payload for one or more requests and responses is going to be examined for tunnel signs.

• Examining the size of the request and answer. Typically, DNS tunneling utilities are pushing to place as much data into the requests and answers as possible. Therefore, the tunneling requests are more likely to have long labels. For instance, there are up to 63 symbols and, in general, long names – up to 255 symbols.
• Disorder of hostnames. DNS names that are authentic commonly contain dictionary words and have some kind of meaning. Names that are encoded are usually out of any order, plus they are even using a set with more characters.
• Statistical Examination. You can detect tunneling by checking the specific character staff of the DNS names. DNS names that are authentic commonly contain fewer numbers. On the other hand, encoded names tend to have a lot of numbers. Examining the percentage of numerical characters in domain names and examining the percentage of the length of the Longest Meaningful Substring (LMS) could also help you.
• Uncommon DNS Record Types. You can check for DNS records that are not usually implemented by a regular client. For example, you can examine the TXT records.
• Violating a policy. In case a policy directs every DNS lookup to pass through an internal DNS server, violations of that policy may be employed as a detection technique.
• Special Signatures. You can use a special signature to examine precise attributes in a DNS header. Then scan for particular content in the payload.

Traffic analysis – The traffic is under examination over time.

• Volume of DNS traffic per IP address. A simple and easy to accomplish technique is to check the specific amount of DNS traffic that is coming from a particular client IP address. 
• Volume of DNS traffic per domain. Another method that is very easy and basic is by checking for massive amounts of traffic towards a precise domain name. DNS tunnel utilities are typically established to tunnel the data by involving a precise domain name. Therefore, all of the tunneled traffic is going to be that exact domain name.
• The number of hostnames per domain. DNS tunneling utilities ask for an individual hostname on every request. That effects by increasing the number unusually compared to a normal authentic domain name.
• Geographic location of DNS server. You can check for a massive amount of DNS traffic that is directed to geographical areas where you don’t offer your services or products.
• The history of a domain. You can examine when an A record (AAAA record) or NS record was created and added to a domain name. That technique is very useful for detecting domain names that are utilized for malicious criminal actions.

Source: GIAC Certifications

Protection against DNS Tunneling attacks

DNS is a crucial service, so it is going to be a problem if you are considering blocking it. Thus, protection against a DNS Tunneling attack involves several actions that are going to help you prevent such an attack.

• You should keep a closer look and track of questionable IP addresses and domain names that are from non familiar sources.
• You can set all of the internal clients to direct their DNS requests (DNS queries) to an internal DNS server. That way, you can filter potential malicious domains. 
• It is very important to stay watchful for any suspicious domain names, and it is best if you always monitor the DNS traffic. That will help reduce the chance for a DNS tunneling attack to appear.
• Establish a DNS firewall for recognizing and stopping any hacker intrusion.
• A real-time DNS solution that is able to detect uncommon DNS queries and unusual traffic patterns on the DNS server is another excellent option.

Using DNS Monitoring against DNS tunneling

DNS Monitoring can be crucial in mitigating the risks of DNS tunneling by providing real-time visibility into DNS traffic patterns and behavior. By constantly analyzing DNS queries and responses, DNS monitoring can detect anomalies and suspicious activities that indicate tunneling attempts. This proactive monitoring allows organizations to quickly identify and respond to potential threats, such as secret data exfiltration and command and control communications before they escalate. Additionally, the ClouDNS Monitoring service offers different alerting mechanisms that notify administrators of any unusual DNS activities. That way, they can take timely action to investigate and block malicious traffic. Thanks to the extensive monitoring capabilities, organizations can strengthen their DNS infrastructure and improve their ability to defend against different threats, including DNS tunneling.

Risks and Impact of DNS Tunneling

DNS tunneling attack poses several significant risks to organizations:

• Data Breaches: Attackers can exfiltrate sensitive information, including personal data, intellectual property, and financial records.
• Unauthorized Access: Allows attackers to maintain hidden, persistent access to compromised systems.
• Operational Disruption: Enables the execution of remote commands, potentially leading to system malfunctions or downtime.
• Financial Loss: Costs associated with data loss, various fines, and restoration efforts can be significant.
• Reputational Damage: Public exposure of breaches can harm an organization’s reputation, leading to loss of customer trust and business.
• Detection Challenges: The nature of DNS tunneling makes it difficult to detect and mitigate, increasing the potential for long-term undetected exploitation.

Examples and Cases

Over the years, several famous examples of DNS tunneling have highlighted its power as a cyber threat:

• Sea Turtle Campaign (2019)

The Sea Turtle campaign in 2019 highlighted the advanced tactics of state-sponsored cyber espionage. This campaign targeted domain registrars, telecommunications firms, and government entities to compromise their DNS records. Attackers manipulated DNS records to redirect legitimate traffic to malicious servers under their control. DNS tunneling played a key role in allowing the attackers to maintain persistent access, exfiltrate sensitive information, and establish C2 channels while remaining undetected.

• SUNBURST Malware (2020)

The SUNBURST malware, a significant component of the SolarWinds supply chain attack in late 2020, demonstrated the sophistication of modern cyber threats. SUNBURST used DNS tunneling as one of its communication methods to establish contact with its C2 infrastructure. By embedding communication within DNS queries and responses, the malware achieved secret data exchange with remote servers. That way, attackers were able to exfiltrate stolen data and receive further instructions while avoiding detection by security measures focused on more traditional communication protocols.

• UDPoS Malware (2015)

The UDPoS malware, discovered in 2015, demonstrated a variation of DNS tunneling where attackers used User Datagram Protocol (UDP) packets to exfiltrate stolen credit card data. The malware encoded the stolen information into DNS queries, which were then transmitted over UDP to avoid detection by traditional network security controls. This technique allowed the attackers to bypass network monitoring tools that usually focus on Transmission Control Protocol (TCP) traffic.

TCP Monitoring vs. UDP Monitoring

Conclusion

DNS tunneling is a severe cyber threat. It could lead to massive negative consequences. This is because the cybercriminal uses the tunnel for malicious ends, like exfiltrating information. In addition, there is no direct association between the cybercriminal and the target. That makes it hard to detect the attacker’s attempt.

The post DNS Tunneling attack – What is it, and how to protect ourselves? appeared first on ClouDNS Blog.

Many IT specialists say that whitelisting leads to better protection, but it has too many limitations. It takes too much time and needs continuous changes. This generates more expenses. On the other side is the blacklisting. You simply put all the problematic devices in a blacklist and they no longer can engage with your network. But can you block all of them?

What is DNS filtering? Do you need it?

Let’s check them out and we later you can make your choice on the “Whitelisting vs Blacklisting” debate.

Blacklisting

Many companies build their business on top of the blacklisting. This is the case of all the antivirus firms. They create a massive list of malware, including every new one there. If we think about it, we can see that it is a very practical approach to the common attacks.

The purpose of blacklisting is often to protect against potential harm, maintain integrity, or enforce compliance with certain standards. It can be implemented by various entities such as companies, organizations, or even governments to restrict access to resources, services, employment opportunities, or other privileges. 

Blacklisting can be used for blocking specific applications and websites. This will reduce the risk that your employees introduce with their actions.

Pros and Cons of Blacklisting

Pros of Blacklisting:

Simple and scalable. Yes, it is basic protection, but it stops many of the attacks. It is also straightforward to apply it to different devices. You just install the software. A system administrator can do it to all of the computers at the same time.

Easy to administrate. The primary responsibility to maintain the blacklist is on the third party (the software provider of the antivirus). The provider is often updating the list and searching actively for new threads while the IT specialists inside the protected company, don’t need to do a thing.

Protection: Blacklisting helps organizations and communities protect themselves by excluding individuals with a history of misconduct or violation from certain activities.

Cons of Blacklisting:

Potential for abuse: There is a risk of false accusations or unfair targeting, leading to the unjust exclusion of innocent individuals or entities.

Lack of due process: Blacklisting can infringe upon an individual’s rights and reputation without providing a fair opportunity for defense or redemption.

Hindrance to rehabilitation: Blacklisting can limit opportunities for personal growth and reintegration, potentially perpetuating a cycle of exclusion.

Whitelisting

Whitelisting is about prevention, not about reacting. People do blacklisting after they have found a problem, whitelisting stops everything except the allowed on the list.

The system administrator can apply the whitelist on the scale of the network. Doing this, they can allow just specific websites or only individual applications. This is good for limiting the threads, but it can affect the work when somebody needs a new app or visit a new site. It will require more work from the admins.

Whitelisting is very practical for remote access. Imagine you want to allow some of your employees to work from home. You can’t use blacklisting, because it will take you forever to block all the IPs from other people, outside of your company. You will use the whitelisting and add just a few IPs (they need to have static IPs).

Pros and Cons of Whitelisting

Pros of Whitelisting:

Enhanced Security: Whitelisting provides a high level of security by only allowing pre-approved programs, applications, or entities to access a system or network.

Prevents Unauthorized Access: By explicitly specifying what is allowed, whitelisting ensures that only trusted and authorized sources can interact with a system, reducing the risk of unauthorized access or malware infiltration.

Granular Control: Whitelisting allows for fine-grained control over what is permitted, allowing administrators to define specific rules and permissions for different entities or processes.

Cons of Whitelisting:

Administration Overhead: Maintaining and managing a whitelist can be time-consuming and require regular updates as new legitimate entities or processes need to be added.

Potential for Overblocking: In some cases, legitimate sources or applications may not be included in the whitelist, leading to unintentional blocking or access restrictions.

False Sense of Security: While whitelisting provides robust protection against unauthorized access, it does not guarantee complete immunity from security breaches, as sophisticated attackers may find ways to exploit authorized entities or processes.

Whitelisting vs Blacklisting table comparison

Examples

Here are some specific examples of whitelisting and blacklisting that may apply to business:

Software:

• Whitelisting: The business limits access to specific applications utilized by select employees for their designated roles. These roles include accounting, human resources, and payroll. Organizations limit access to these applications to the machines or servers dedicated to these functions.
• Blacklisting: The business blocks access to games or applications that could potentially contain malware or pose security risks to the company’s systems.

Email:

• Whitelisting: The business configures its email system to only receive emails from trusted sources, such as clients or internal employees, ensuring that important communications are not missed.
• Blacklisting: The business blocks domains or email addresses known for sending spam, junk, or phishing emails, protecting the company’s network and employees from potential security threats.

DMARC, the solution for your phishing problems

Websites:

• Whitelisting: The business restricts access to specific websites that are essential for employees to perform their job functions, such as accounting-related sites or industry-specific resources.
• Blacklisting: The business blocks access to websites that may interfere with workplace productivity or pose security risks, such as pornography sites, gaming platforms, or social networking sites.

These examples illustrate how businesses can implement whitelisting and blacklisting to enhance security, productivity, and compliance with company policies.

What is Greylisting?

Greylisting is an SMTP-based email filtering technique used to combat spam. When an email is received from an unknown sender or IP address, the receiving mail server temporarily rejects the message with a “soft bounce” response, specifically a temporary SMTP error code (usually 4xx). Legitimate email servers are designed to retry sending the email after a specified delay, typically within a few minutes or hours. In the meantime, the greylisting server records the details of the incoming email (sender, recipient, and IP address) and adds them to a temporary whitelist. Once the email is re-sent, the server checks the whitelist and, if the details match, accepts the message. Greylisting exploits the fact that most legitimate email servers will retry delivery, while many spam systems do not, thereby effectively reducing spam volumes. However, this technique may introduce a slight delay in email delivery due to the initial rejection and delay period.

Whitelisting and Blacklisting with AI, ML, and Blockchain

The evolution of technology continuously shapes the effectiveness and implementation of whitelisting and blacklisting:

• Artificial Intelligence (AI) and Machine Learning (ML): AI and ML are revolutionizing whitelisting and blacklisting by enabling dynamic lists that can adapt based on behavior patterns and emerging threats. For example, AI can automate the process of updating whitelists with legitimate applications or detect anomalies that might indicate a need to blacklist new threats. These technologies are particularly effective in environments where security needs to quickly adapt to new and evolving challenges.
• Blockchain Technology: Some security platforms are starting to utilize blockchain to manage and securely distribute whitelists and blacklists. Because blockchain data is immutable and transparent, it can provide a secure, decentralized method for managing these lists that is resistant to tampering and fraud. This application of blockchain in cybersecurity leverages its inherent strengths to enhance the integrity and reliability of traditional security measures.

Conclusion

Whitelisting vs Blacklisting, did we find which is better? No, they have their good and bad sides. The best option is a combination of the two, depending on your IT specialists’ capacity. You can use antivirus software (blacklisting) and block some specific list of websites that you don’t want to be accessible from your company. At the same time, you could use whitelisting for your remote access and more sensitive data inside your company.

The post Whitelisting vs Blacklisting, preventing or reacting appeared first on ClouDNS Blog.

What is a Single Point of Failure (SPOF)?

A Single Point of Failure (SPOF) is a critical component within a system that, when it fails, causes the entire system to stop operating. This vulnerability exists because the component does not have a redundant counterpart in the system that can take over its function in the event of a failure. SPOFs can exist in various forms across different systems:

Physical SPOFs are common in hardware-related scenarios where a single piece of equipment, like a hard drive, server, or power source, supports critical operations without any backup. If this equipment fails, the system relying on it cannot continue to function, leading to potential service interruptions and operational losses.

Software SPOFs occur when critical applications, databases, or operating systems have no fail-safe or backup system. For instance, a software application that handles all data processing tasks for a business without any alternative systems to handle these tasks if the primary software fails.

Network SPOFs arise from the design of the network architecture. A typical example is a single router or switch through which all network traffic passes. If this device fails, all network communication could be disrupted, isolating parts of the network or even bringing the entire network down.

Human SPOFs appear when a particular task or decision-making process is dependent only on one person or team. If that individual or team is not available due to illness, resignation, or any other reason, their absence can disrupt processes and decision flows, affecting the organization’s operations and strategic actions.

Examples

Here are some examples of Single Point of Failure (SPOF) in various technological and organizational environments:

Single Server

A company uses a single server to host its entire website and all associated data. This server is crucial to the company’s online operations, including e-commerce, customer support, and communications. If the server experiences a hardware failure, the website will become completely inaccessible. This disruption could lead to significant financial losses, especially during high-traffic periods like sales or product launches. To mitigate this risk, companies should implement redundant server systems, ensuring that a backup can immediately take over without disrupting operations.

Improve redundancy with Anycast DNS

Lone Network Switch

In an office setting, all workstations, printers, and other networked devices are connected through a single network switch. If this switch fails due to electrical issues, overheating, or physical damage, all devices will lose connectivity. This failure would block all digital communication and access to network resources, severely impacting productivity and potentially causing data loss if work in progress is not saved externally. To prevent such disruptions, organizations can install multiple switches and configure them for failover, ensuring continuous network availability even if one switch fails.

Critical Software Application

A financial services firm relies on a single software application for processing transactions and managing client accounts. If this application experiences a bug or a failure, it can prevent the firm from executing transactions, accessing critical client data, and complying with regulatory requirements. Such a situation could not only lead to financial and reputational damage but also legal consequences. Implementing application redundancy can help mitigate these risks.

Key Personnel

An organization may rely heavily on a single individual who possesses unique skills or knowledge crucial for certain operations or decision-making processes. If this individual becomes unavailable due to unexpected circumstances like illness or resignation, their absence can affect critical activities. Developing a succession plan and cross-training employees can help ensure that the organization has multiple people capable of filling critical roles.

The Impact of a Single Point of Failure

The negative effects of a Single Point of Failure (SPOF) can be extensive and damaging to any organization. Here are some of them:

Downtime and Service Disruptions

One of the most immediate and visible effects is downtime. For example, if a critical server fails, all services and operations hosted on that server can become non-functional until the problem is resolved. This can lead to significant operational disruptions, affecting everything from customer service to internal communications. Prolonged downtime can lower customer trust and satisfaction, leading to a decline in user retention and potentially causing permanent damage to the business’s reputation.

Security Vulnerabilities and Breach

Single points of failure are not only operational risks but also security risks. Systems with SPOFs may lack the necessary redundancies that help protect against cyber threats. When attackers identify and exploit these vulnerabilities, the effects can be catastrophic. It can lead to unauthorized access, data breaches, and loss of sensitive information.

Financial Impact

The costs associated with SPOFs are significant. Direct costs include lost sales and productivity during downtime, as well as the expenses for repairing or replacing faulty components and systems. Indirect costs can be even more, including long-term losses from decreased customer loyalty. 

Damage to Reputation

The damage to an organization’s reputation after incidents can be one of the most challenging consequences. Reputation damage affects not only customer perception but also investor confidence and market value. Recovery from such damage requires effective marketing and customer service efforts and, more importantly, improvements in the resilience of the organization.

How to Identify a Single Point of Failure?

Identifying SPOFs requires a systematic approach to analyze all system components and their dependencies. This analysis should include:

• Physical Components: Checking for any single physical component whose failure could cause downtime to the entire system.
• Software Systems: Ensuring there are no single pieces of software or databases critical to operations without redundancy.
• Human Factors: Evaluating if any process excessively relies on a single person or team.

Some techniques can be crucial in identifying potential failure points in a system:

• Systematic Inventory and Documentation: Document all components of your infrastructure, including hardware, software, network configurations, and human resources. The comprehensive inventory will be the foundation for identifying critical elements without redundancy.
• Critical Component Analysis: Evaluate each component’s role within the operational ecosystem. Determine the impact of its failure by asking questions such as: What processes would be affected? How would a failure affect service delivery? The analysis helps pinpoint components that carry the highest risk if they fail.
• Dependency Mapping: Use dependency maps to visualize how different components and systems interact. These maps help identify dependencies where a single component’s failure could lead to cascading effects across other systems. 
• Failure Mode and Effects Analysis (FMEA): Implement FMEA to systematically evaluate potential failure modes of each component and their effects on other parts of the system. This analysis includes reviewing historical failure data, which can help prioritize the components based on their likelihood of failure and the severity of their impact.

How to Eliminate Single Point of Failure?

Once Single Point of Failure (SPOF) has been identified, the next critical step is to implement strategies to mitigate or eliminate these vulnerabilities. Here is how to achieve it:

• Comprehensive Risk Assessments: Regular and in-depth risk assessments are crucial. These assessments should not only identify current vulnerabilities but also predict potential future challenges that could arise from changes in technology or business processes. Risk assessments help prioritize which SPOFs need immediate attention based on their potential impact on the business.
• Redundancy and Failover Mechanisms: Building redundancy involves adding additional resources that can take over the function of a failed component without user intervention. This might include additional hardware, such as servers or network paths, or software solutions, such as database replicas. Failover mechanisms, both automatic and manual, should be tested regularly to ensure they activate properly in case of a component failure.
• Load Balancing: Distributing the workload across multiple systems can prevent any single server or network device from becoming a bottleneck. Load balancing enhances performance and availability, reducing the risk of overloads on individual components which could lead to failure.
• Regular Monitoring: Continuous monitoring of system performance and health can prevent many issues before they escalate to critical failures. Use monitoring tools that provide real-time insights into system operations and set up alerts for anomalies. 
• Security Updates and Patch Management: Keep all systems updated with the latest security patches and updates. Cyber vulnerabilities can be exploited to create failures within critical systems. A robust patch management policy is essential for protecting against external threats and reducing the likelihood of security-related system failures.
• Backup Power Solutions: Implementing uninterruptible power supplies (UPS) and generators ensures that critical systems and components remain operational during power outages. This is particularly important for data centers, hospitals, and other critical infrastructure that rely heavily on power supply.
• Disaster Recovery Planning: Develop and maintain a comprehensive disaster recovery plan that includes detailed procedures for restoring systems and data in the event of a failure. 

Conclusion

Identifying and eliminating Single Point of Failure (SPOF) is crucial for maintaining the operational integrity and security of systems across various industries. By investing in robust systems, incorporating redundancy, and keeping vigilant monitoring and regular updates, organizations can safeguard against significant disruptions and security breaches. Understanding and mitigating SPOFs not only prevents financial and reputational damage but also enhances the overall security posture of the organization.

The post Single Point of Failure (SPOF): How to Identify and Eliminate It? appeared first on ClouDNS Blog.

DMARC explained

DMARC is an authentication, policy and also reporting protocol. It uses both SPF and DKIM and adds linkage to the “From” domain name, policies for handling the incoming email in case of failure and something very important – report for the sender. That way the sender can see if there is a problem, and act on it.

The main purpose of DMARC is to protect against direct domain spoofing. If an attacker tries to send email from not authorized, DMARC will detect it and block it.

Combined with BIMI, you will also give proper protection to your brand reputation by providing authentic messages.

Why SPF and DKIM are not enough?

SPF – Sender Policy Framework has the goal to validate the senders’ servers. The receivers check the SPF record and see the IP address. It should be matching the IP address of the domain of the sender.

A problem with the SPF is that the SPF record applies to the return path of the domains, not to the domain, that shows in the “From” on the user interface. DMARC fixes this flaw with alignment, a match, between the visible “From” and the server authenticated by SPF.

DKIM – DomainKeys Identified Mail. The owner can use DKIM record to sign the emails that it sends. The emails will have extra data (encrypted) in the header that can be verified through the DNS. This technology is not flawless too. Many companies don’t rotate the key, and that can be a big problem. This is another thing, DMARC fixes. It provides rotating keys.

How does DMARC work?

We mention already that DMARC uses policies. The administrator sets them, defining the email authentication practices and what should the receiving email server do if an email violates a policy.

When the receiving email server gets a new email, it makes a DNS lookup to check the DMARC record. It will look for:

• If the DKIM signature is valid.
• The IP address of the sender, if is one of the allowed by him (SPF record).
• If the header shows proper “domain alignment”.

With all of the above in consideration, the server DMARC policy to accept, reject or flag the email.

In the end, the server will send a message to the sender with a report.

Benefits of DMARC

Here are some of the main advantages of implementing this advanced protocol.

For the sender:

• Shows that the email uses authentication – SPF and DKIM.
• Receives a feedback about the sent email.
• Policy for failed email.

For the receiver:

• Provide authentication for the incoming emails
• Evaluating the SPF and DKIM
• See what the sender prefer – policy
• Returns feedback to the sender

DMARC Record example

DMARC records are a simple text (TXT) DNS records. They look like this:

“v=DMARC1;p=reject;pct=100;rua=mailto:postmaster@dmarcdomain.com”

• V – the version of the protocol. In the example is version 1
• Pct – % of the messages that are subject to filtering (pct=20)
• Ruf – URI for forensic reports (ruf=mailto:authfail@example.com)
• Rua – URI for aggregate reporting (rua=mailto:aggrep@example.com)
• P – Policy, organizational domain (p=quarantine)
• Sp – Policy, subdomains of the organizational domain (sp=reject)
• Adkim – Alignment for DKIM (adkim=s)
• Aspf – Alignment for SPF (aspf=r)

DMARC record generator by ClouDNS

Why use DMARC?

DMARC is a protocol used to help prevent email fraud and phishing attacks. Here’s why it’s important and why you should use it:

• Prevention of Email Spoofing: It helps prevent attackers from spoofing your domain, a common tactic in phishing attacks. By authenticating emails sent from your domain, DMARC ensures that only authorized senders can use your domain name.
• Improved Email Deliverability: Implementing it can help improve your email deliverability by reducing the chances of your legitimate emails being flagged as spam or being rejected by email servers. When email receivers see that your domain is protected by DMARC, they are more likely to deliver your emails to the inbox.
• Protection of Brand Reputation: Phishing attacks that use your domain can harm your organization’s reputation and trustworthiness. DMARC helps protect your brand reputation by preventing unauthorized use of your domain in phishing emails, thereby maintaining trust with your customers and partners.
• Visibility and Control: DMARC provides visibility into email traffic sent from your domain through reporting mechanisms. You can monitor email authentication results and receive reports on email activity, including information about legitimate and fraudulent email senders. This allows you to take proactive measures to protect your domain and email infrastructure.

What is an MX record?

Conclusion

DMARC can significantly lower the number of fraud emails and spam. It is not 100% bulletproof, but it adds a lot of extra protection in comparison with the other two solutions – SPF and DKIM. The reporting functionality is welcome plus too.

The post DMARC, the solution for your phishing problems appeared first on ClouDNS Blog.

DNS Monitoring explained

DNS Monitoring gives you the ability to manage and examine the performance of a DNS server. The main goal is to assist you with detecting server-side and client-side DNS issues. In addition, it guarantees the health of DNS servers by sending a DNS request. You are able to choose different query types depending on the DNS record you want to check, for example, A, AAAA, MX, NS, PTR, or CNAME. Then you specify a required expected response that is compared to the actually received response.

DNS Monitoring has a very important role in your network Monitoring service. Moreover, it ensures the safety and proper connection between the end-users and the website or service that they want to use. It is extremely useful when it comes to the fast detection of unpleasant issues or for recognizing potential security breaches. Additionally, it is helpful for stopping some popular malicious attacks. Thanks to the regular checks, you can effortlessly detect unexpected issues or localize DNS outages. As a result, you can prevent a large negative impact on your website or on the safety of your users that want to reach your services by detecting and resolving the problem fast.

Why is DNS Monitoring important?

The Domain Name System (DNS) is an essential part of the Internet. Yet, it was not designed with security in mind. For that reason, cybercriminals have developed ways to take advantage of its vulnerabilities. Therefore, DNS monitoring is vital for helping you protect your online presence and catch issues before they become significant problems. DNS monitoring gives you the ability to recognize several different DNS errors. The majority of them result from malicious attempts and could be a significant threat to your security. On the other hand, there are also communication flow interruptions. They compromise the functionality of your domain’s DNS resolution process and lower the traffic toward your site.

Configuration Errors

DNS Monitoring can detect errors like incorrect IP addresses and assure that outages are not prolonged. The less time your website or service is down, the less your traffic flow is interrupted. That way, you can maintain and increase your uptime, and every user that wants to reach your website (or service) will have that opportunity without any difficulties.

A configuration error can stop users from reaching your website and make it seem like their internet is not acting correctly. This could drive traffic away from your domain and meddle with your business.

DNS Spoofing (DNS poisoning)

DNS Spoofing, also commonly known as DNS poisoning, is a popular cyber threat that cybercriminals use. Recursive DNS servers hold the hostname data with all related DNS records for a particular amount of time (depending on the TTL). That way, they operate more efficiently because they do not repeat the resolution process for the same IP address. However, it also leads to vulnerabilities.

Cybercriminals insert fraudulent data into the DNS cache on the server, like fake IP addresses. Commonly, that is achieved due to viruses and malware. As a result, the users’ requests are directed to a malicious phishing website, which looks similar to the original one. There they type their sensitive information, such as passwords, credit card details, etc. A lot of people do not even notice that they have been directed to malicious pages. No one wants to put its clients at risk of phishing schemes. Additionally, compromising user information can seriously impact your business.

DDoS and DoS Attacks

Distributed Denial of Service (DDoS) and Denial of Service (DoS) attacks are massive cyber threats that are able to bring down your server. They involve large amounts of fake traffic with the main goal of overcoming your resources and making your website or service unavailable for regular users. It is important to mention that the earlier the attack is detected, the more quickly it can be handled. Therefore, it is best to stop it before the DNS records on the server become weaponized by the cybercriminals.

DNS Tunneling

DNS Tunneling is another cyber threat that attackers commonly use. Typically, DNS servers handle a massive amount of traffic, and there are no security measures regarding the exchanged data packets. DNS Monitoring can help detect tunneling and serve to prevent any further data from being exchanged. This is an essential addition to your existing security measures.

DNS outage

DNS outage does not allow your users to connect and reach your website or service. It is possible to last just several minutes, but it could continue up to several hours or even days. So you can probably imagine how seriously it can affect your business and services. With DNS Monitoring, you can easily find and understand where the issue is coming from and quickly fix it.

How does it work?

You can find DNS monitoring as a part of ClouDNS Monitoring service. It works by regularly checking if the DNS server responds to all DNS queries. With such type of check, you can initiate DNS queries for a desired hostname and query type – A (for IPv4), AAAA (for IPv6), MX, NS, PTR, or CNAME. There are two scenarios that follow once you set your expected response.

• The check is marked UP, when the received response is equal to the required expected one.
• The check is marked DOWN, when the received response is not equal to the required expected one.

The DNS monitoring check validates the conditions of DNS servers by sending a DNS request and comparing the received response with the expected one.

You can also take a look at our article about DNS monitoring Checks!

Why do you need it?

DNS monitoring is necessary because DNS performance is essential to your network, servers, and applications. Thanks to the DNS servers, your website or service works effectively and efficiently, yet they should be monitored for vulnerabilities. In case you neglect their adequate supervision, you may compromise both the security of your business and your clients.

With the ClouDNS Monitoring service, you can keep an eye on your servers and quickly detect any issues. As you know, timing is crucial, so the fast resolving of the issues is going to guarantee the integrity of your servers. So, as a result, everything should continue operating smoothly.

Benefits of DNS monitoring

DNS monitoring is a critical component of any organization’s network management strategy. By monitoring DNS traffic, organizations can proactively identify and address issues before they escalate. Here are some of the main benefits of the implementation of DNS monitoring:

• Improved Server Availability

It can help improve server availability by identifying and resolving issues that can cause downtime or service disruptions. For example, DNS servers can be vulnerable to hardware or software failures, network connectivity issues, and cyber attacks, which can affect the availability of websites and other online services. DNS monitoring services can detect and alert tech teams of problems before they escalate, allowing them to take proactive measures to resolve them.

• Improved DNS Server Troubleshooting

DNS monitoring can help improve DNS server troubleshooting by providing visibility into the DNS infrastructure and the flow of DNS queries. Tech teams can use DNS monitoring tools to identify blockages, misconfigurations, and other issues affecting the performance of the DNS server. The information helps them troubleshoot and resolve issues more quickly, minimizing downtime and service disruptions.

• Faster Detection of Outages

DNS monitoring can be useful for detecting outages faster by providing real-time visibility into the DNS infrastructure. It can alert tech teams about issues, such as DNS server failures or network connectivity problems, as soon as they occur. That way, IT teams can quickly identify the root cause of the problem and take action to restore services.

Monitoring Plan

Comparison with other monitoring techniques

DNS monitoring is a specialized approach focusing on the health and security of the Domain Name System, which is crucial for translating domain names into IP addresses. While DNS monitoring is vital, it’s one part of a broader network monitoring strategy that includes other techniques such as network performance monitoring, application monitoring, and security information and event management (SIEM). Here’s how DNS monitoring compares with other monitoring techniques:

• Network Performance Monitoring (NPM): NPM tools focus on the performance and availability of networks and network components (like routers and switches). While NPM can identify network congestion and hardware failures that indirectly affect DNS services, DNS monitoring directly assesses DNS health, ensuring that domain name resolution processes are working as expected.
• Application Monitoring: This technique focuses on the performance and availability of specific applications. It can help identify issues within an application that may impact user experience but doesn’t directly monitor DNS processes. DNS monitoring complements application monitoring by ensuring that users can reach the applications in the first place.

Security Information and Event Management (SIEM): SIEM systems collect and analyze aggregated log data from various sources to detect and respond to security incidents. While SIEM can identify security breaches that may indirectly affect DNS services, DNS monitoring provides specific insights into DNS-related security threats, such as DNS spoofing or tunneling attacks.

Conclusion

So, now you know what DNS Monitoring is and why it is so important for your security. First, there are different criminal attempts that could be prevented when you keep an eye on your servers. Additionally, it is beneficial for simplifying the process of finding and fixing network issues. Finally, it helps you prepare and not be surprised in such situations.

The post Monitoring your DNS, should you do it? appeared first on ClouDNS Blog.

What is DNS Hijacking?

DNS hijacking, also known as DNS redirection, is a malicious cyber attack that redirects internet traffic away from its intended destination and redirects it to a malicious website. This is achieved by modifying the DNS server’s settings or by compromising the user’s computer or network. 

When you type a website’s domain name into your web browser, your computer sends a DNS request to find the IP address associated with that domain name. In a DNS hijacking attack, the attacker replaces the legitimate IP address with their own, sending the user to a fake website that may look identical to the real one.

DNS hijacking can be used for various malicious purposes, such as phishing, stealing sensitive information, or spreading malware. Therefore, it is a serious threat to internet security and can affect anyone.

How does it work?

Cybercriminals can execute different strategies to complete their malicious goal. However, some of the main steps involved in a DNS hijacking attack are the following: 

1. The attacker gains access to the victim’s computer or network, either by exploiting a vulnerability or through social engineering techniques such as phishing.
2. The attacker then changes the computer’s DNS settings or modifies the DNS server to point to a malicious DNS server controlled by the attacker.
3. When the user tries to access a website, the request is sent to the malicious DNS server instead of the legitimate DNS server.
4. The malicious DNS server responds with a fake IP address corresponding to a malicious website instead of the actual website the user intended to visit.
5. The user’s computer then connects to the fake IP address and is redirected to a fake website. It usually looks like the legitimate one, yet the attacker controls it.
6. The attacker can then steal the user’s sensitive information, such as login credentials, credit card details, or other personal data.
7. The attacker can also use the fake website to distribute malware or launch further attacks.

Types of DNS Hijacking Attacks

There are several types of DNS hijacking attacks that attackers may use to redirect traffic and compromise users’ security. Here are some of the most common types:

• Local DNS hijack: This type of attack involves modifying the DNS settings on a single computer or device, usually by malware. The attacker changes the DNS settings to point to a DNS server controlled by the attacker, which can redirect the user to malicious websites.
• Router DNS hijack: This attack targets the DNS settings on a router, which can affect all devices connected to the network. The attacker gains access to the router’s DNS settings, usually by exploiting a vulnerability or guessing a weak password. Then it modifies the DNS setting so that they point to a DNS server that is under its control.
• Man-in-the-middle DNS attack: It involves intercepting and modifying DNS requests and responses in transit between the user’s computer and the legitimate DNS server. The attacker can modify the DNS response to redirect the user to a malicious website or intercept sensitive information entered by the user.
• Rogue DNS Server: In this type of attack, the attacker hacks a legitimate DNS server and then modifies DNS records to redirect DNS requests to a malicious website. This can be done by exploiting vulnerabilities in the DNS software or by using social engineering techniques to gain access to the server.

How to Protect from DNS Hijacking

For Name Servers and Resolvers

Protecting name servers and resolvers from DNS hijacking is critical to ensure the security and availability of the DNS infrastructure. Here are some additional steps that can be taken to protect against DNS hijacking:

1. Install Firewalls Around Your DNS Resolver: Firewalls can be used to restrict access to your DNS resolver to authorized sources only. By implementing firewalls, you can block traffic from unauthorized sources, reducing the risk of DNS hijacking.
2. Increase Restrictions on Access to Name Servers: Restricting access to name servers can limit the potential attack surface for DNS hijackers. Access to name servers should be limited to only those who need it, and access should be protected with strong passwords and two-factor authentication (2FA).
3. Fix Known Vulnerabilities: It’s important to keep your DNS resolver and name servers up-to-date with the latest security patches and fixes. This helps to ensure that any known vulnerabilities are addressed, reducing the risk of exploitation by attackers.
4. Use encrypted DNS: Encrypted DNS protocols like DNS-over-HTTPS (DoH) and DNS-over-TLS (DoT) can help protect against DNS hijacking by encrypting DNS traffic between clients and resolvers. This makes it more difficult for attackers to intercept and manipulate DNS traffic.
5. Avoid Zone Transfers: Zone transfers, which allow name servers to exchange information about DNS zones, can be used by attackers to gather information that can be used in DNS hijacking attacks. Limiting or disabling zone transfers can help prevent this type of attack.

For website owners 

As a website owner, there are several measures you can take to protect your website from DNS hijacking. Here are some steps you can follow:

1. Control DNS access: Limit DNS access to a selected few IT team members with multi-factor authentication when accessing the domain name server registrar. To further enhance security, whitelist only specific IP addresses to access the domain name registrar.
2. Enable Client Lock: Some DNS registrars use client locks to prevent unauthorized DNS record changes. This feature disables the option to modify DNS records unless a request is made from a precise IP address.
3. Choose a reputable DNS service: Choose a DNS service with a reputation for reliability and security.
4. Implement DNSSEC: DNSSEC adds an additional layer of security to the DNS system. It helps prevent DNS hijacking by verifying the authenticity of DNS records. Implementing DNSSEC can protect your website from various DNS attacks, including DNS cache poisoning and man-in-the-middle attacks.
5. Monitor DNS activity: Regularly monitor your DNS activity to detect any unusual activity or unauthorized changes. Set up alerts for any suspicious DNS activity, and take immediate action if any unauthorized changes are detected.

Monitoring service plans from ClouDNS

For end users 

End users can also take steps to protect themselves from DNS hijacking. Here are some ways end users can protect themselves:

1. Protect your internet traffic with a VPN: A fast Virtual Private Network (VPN) can help safeguard your internet traffic by encrypting it and routing it through a secure tunnel, which makes it challenging for attackers to intercept your DNS queries.
2. Clear your DNS cache: Clearing your DNS cache periodically can prevent attacks that use DNS cache poisoning to redirect your internet traffic to malicious sites.
3. Watch out for suspicious emails and links: Make sure not to click on links in emails from unknown senders or unfamiliar websites, as they could lead to sites that could hijack your DNS.
4. Verify website security before entering sensitive data: Verify the URL of a website before entering any sensitive information. Look for the padlock icon in the address bar, which indicates that the website uses HTTPS encryption to protect your data.
5. Keep your antivirus software updated: Ensure your software is updated to the latest version, as it can help detect and remove malware that may be used to carry out DNS hijacking attacks.
6. Change your passwords frequently: It’s a good practice to change your passwords regularly, especially for important accounts. That way, you minimize the risk of an attacker gaining access to your accounts through DNS hijacking.

Consequences of DNS hijacking

DNS hijacking can have severe negative effects on both individuals and organizations. Here are some of them:

• Identity Theft and Fraud: The attack can redirect users to malicious websites that imitate legitimate ones. Attackers can then steal sensitive information such as login credentials, financial data, or personal information, leading to identity theft and financial fraud.
• Data Breaches: By redirecting traffic to fraudulent websites, attackers can also inject malware onto users’ devices. This malware can compromise the security of personal and sensitive data stored on the device, leading to data breaches with potential consequences for both individuals and organizations.
• Disruption of Services: DNS hijacking can disrupt the normal functioning of websites and online services by redirecting legitimate traffic to malicious servers or by causing DoS (Denial-of-Service) attacks. This can result in downtime, loss of productivity, and damage to the reputation of businesses and organizations.
• Damage to Reputation and Trust: When users encounter problems accessing a website due to DNS hijacking, they can lose trust in the affected organization’s ability to maintain a secure online presence. Customers may perceive the organization as unreliable or insecure, leading to reputational damage that can be difficult to restore.
• Financial Losses: Mitigating the effects of DNS hijacking requires direct costs, such as investigation and implementation of security measures. Apart from that, organizations may also face financial losses due to decreased customer trust, missed business opportunities, and potential legal liabilities resulting from data breaches or regulatory non-compliance.

Conclusion

In conclusion, DNS hijacking is a serious cyber attack that can have severe consequences, including stealing sensitive information and redirecting users to malicious websites. However, by being aware of the risks and taking preventative measures, you can safeguard your online security against this malicious attack.

The post DNS Hijacking: What It Is and How to Protect Yourself appeared first on ClouDNS Blog.

What is a Phishing attack?

A phishing attack is a malicious attempt by cybercriminals to deceive individuals into providing sensitive information through fraudulent emails, messages, or websites. The attackers disguise themselves as trustworthy entities, such as banks, social media platforms, or government agencies, to gain victims’ trust and exploit their vulnerability for personal gain.

How does it work? Step by step

Here’s how a typical phishing attack unfolds:

1. Bait Creation: The first step in a phishing attack involves creating an enticing bait, such as an urgent request to update account information, a tempting offer, or a warning about a compromised account.
2. Delivery: The bait is then delivered through various means, such as email, SMS, social media messages, or even malicious ads.
3. Deception: The message typically contains a sense of urgency or fear, compelling the recipient to take immediate action without questioning its legitimacy.
4. Linking to fake websites: Phishing emails often include links to fake websites that closely resemble legitimate ones. These fake sites are designed to collect the victim’s login credentials and personal information when entered.
5. Data collection: Once the victim enters their information, the cybercriminals capture it and can use it for identity theft, financial fraud, or other malicious purposes.

Types of phishing attacks

There are several variations of phishing attacks, including:

• Email phishing: The most common type, where fraudulent emails are sent to deceive recipients into revealing sensitive information.
• Spear phishing: Highly targeted attacks aimed at specific individuals or organizations, often using personalized information to appear more convincing.
• Whaling attacks: Similar to spear phishing but focused on high-profile individuals or executives within an organization.
• Clone phishing: Attackers create a replica of a legitimate email and modify it to include malicious content or links.
• Pharming: Redirects victims to fraudulent websites even if they enter the correct web address.

How do spear phishing attacks differ from standard phishing attacks?

Standard phishing attacks cast a wide net, sending mass emails or messages impersonating well-known entities to deceive as many victims as possible. These attacks use generic content and fake websites to trick recipients into revealing personal information.

In contrast, spear phishing attacks are highly targeted and personalized. Cybercriminals gather specific details about their victims, crafting convincing messages that appear to come from trusted sources like colleagues or business partners. This tailored approach increases the likelihood of success, as victims are more likely to fall for the authenticity of the communication, leading to the disclosure of sensitive data or malware installation.

2023 Phishing attack Statistics

According to a staggering statistic from IT Governance, an estimated 3.4 billion malevolent emails, mainly in the form of phishing, hit our inboxes every single day, marking it as the predominant form of cybercrime (IT Governance, 2023). The objective? To ensnare unsuspecting individuals into revealing their login credentials. IBM’s Cost of a Data Breach Report further sheds light on this issue by revealing that stolen credentials, indeed, represent the primary cause of data breaches, accounting for 19% of all cyber attacks (IT Governance, 2023).

The threat intensifies when we shift our gaze towards corporate security. A report by Digital Guardian has identified that a staggering 90% of corporate security breaches can be traced back to phishing attacks (IT Governance, 2023). The toll on organizations is heavy. Each piece of personal information pilfered via a phishing attack, according to Venari Security, translates to an approximate loss of $181. (IT Governance, 2023).

Source: 51 Must Know Phishing Statistics for 2023, IT Governance

Source: Most Affected Industries by Phishing, Statista

In the ever-evolving landscape of phishing attacks, certain industries tend to be more targeted than others. Statista, a leading provider of market and consumer data, provides an illuminating infographic that delineates the sectors most affected by phishing.

Leading the pack, unsurprisingly, is the financial industry with 23% of phishing attempts directed towards it. This is due to the sensitive and valuable information that this sector holds, making it an attractive target for cybercriminals.

Next up, the Software-as-a-Service (SaaS) and webmail industries face their fair share of threats with 17% of the phishing attacks aimed at them. This might be attributed to the fact that many SaaS companies hold vast amounts of data on behalf of their clients, making them a rich source for phishing attempts.

What is IaaS, PaaS, and SaaS?

Social media platforms are the third most targeted, suffering from 11% of these malicious attempts. The extensive personal and business data that users tend to share on these platforms make them a fertile ground for cybercriminals.

Logistics and shipping sectors, along with e-commerce and retail, each receive 6% and 4% of the phishing attempts respectively. The payment sector is also targeted by 4% of phishing attacks. These industries, dealing with sensitive transactional data, are enticing for hackers who want to exploit the financial and personal information.

The telecom sector, with a share of 3%, and the burgeoning cryptocurrency industry, receiving 2% of phishing attempts, round out the list. It is worth noting that as the popularity of cryptocurrencies continues to grow, they may become an even more lucrative target for phishing in the future.

Impacts of Phishing Attacks

The consequences of falling victim to a phishing attack can be severe and extensive. For individuals, the theft of personal information can lead to identity theft, financial loss, and damage to personal reputation. In the context of organizations, phishing attacks can result in data breaches, financial fraud, disruption of operations, and loss of customer trust.

Beyond immediate financial and reputational harm, phishing attacks can also be used to launch more advanced cyber threats, such as ransomware, malware infections, and business email compromise (BEC) scams. By compromising the credentials of unsuspecting users, attackers gain access to organizations, enabling them to launch more sophisticated and targeted attacks.

Moreover, the indirect costs associated with phishing attacks, including incident response, remediation efforts, and regulatory fines, can be significant burdens on organizations of all sizes. The reputational damage from a successful phishing attack can ruin an organization’s brand and lose customer trust, potentially leading to long-term business consequences.

How to protect against Phishing Attack?

There are several proactive steps you can take to protect yourself against phishing attacks:

• Anti-phishing software: This type of software can identify phishing content and alert users about potential threats.
• Two-Factor Authentication (2FA): This adds an extra layer of security by requiring two types of identification before granting access.
• Monitoring service: With Monitoring service you can keep an eye on your personal data online and alert you if they detect unusual activity.
• DNS records: You can implement SPF, DMARC, DKIM, and PTR records. These email authentication methods help protect against email spoofing and increase email security.
• rDNS: Reverse DNS lookup can verify whether the server is associated with the domain it claims to represent.
• HTTPS and SSL certificates: Look for ‘https‘ in the URL and the padlock symbol in the browser for an SSL certificate that can help to identify secure websites. Phishing websites often lack these security measures, providing users with visual cues of a potential threat. 
• Education and awareness: Regular training on phishing attack recognition and safe online habits can be crucial for both businesses and individuals.
• Regular software updates: Keeping your software and systems updated ensures you have the latest security patches, making it harder for attackers to exploit vulnerabilities.

Famous Phishing Attacks

Here are some of the most popular examples of Phishing attacks:

• Target Corporation (2013)

In late 2013, Target, one of the largest retail chains in the United States, fell victim to a sophisticated phishing attack that led to massive consequences. The attack began with a phishing email sent to an HVAC vendor that had access to Target’s network. The attackers then used the compromised vendor credentials to gain entry into Target’s systems. Ultimately, the breach resulted in the theft of over 40 million credit card numbers and personal information of 70 million customers. The incident highlighted the potential cascading impact of phishing attacks on large organizations.

• Sony Pictures (2014)

In 2014, Sony Pictures Entertainment became the target of a highly publicized cyber attack. While the attack included elements beyond phishing, it was initiated through a carefully prepared email. The attackers sent phishing emails to Sony employees, tricking them into revealing login credentials. Afterwards, the attackers unleashed malware that disabled Sony’s computer systems, leading to the exposure of sensitive internal documents, emails, and unreleased films. The incident highlighted the potential for phishing to be a precursor to more extensive and damaging cyber intrusions.

• Facebook and Google (2017)

In 2017, a Lithuanian hacker produced a phishing attack targeting tech giants Facebook and Google. The attacker posed as a legitimate vendor and successfully convinced employees at both companies to wire over $100 million in payments for supposed goods and services. The scam involved fake invoices and email correspondence that appeared to be from reputable suppliers. The incident highlighted the vulnerabilities in the supply chain and payment processes of large corporations, emphasizing the need for strict verification procedures.

Conclusion

The landscape of cybercrime, particularly phishing, is ever-evolving. Therefore, staying informed and proactive in adopting protective measures is crucial. With the knowledge of how phishing works, what the current trends are, and how to defend against these attacks, individuals and organizations can greatly enhance their cybersecurity stance.

The post Understanding Phishing Attack and How to Stay Protected appeared first on ClouDNS Blog.