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.

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.

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.