With internet censorship becoming more widespread, many people turn to domain fronting for accessing blocked or censored content. But there is a problem. Cybercriminals are beginning to use this technique to hide malicious activities from detection.
For example, in a recent cyber attack, a Russian hacker group, APT29, employed domain fronting to obfuscate their activities and avoid detection. With the Tor network’s help, they could communicate with infected machines and extract data.
The hackers were able to disguise their malicious traffic as legitimate traffic. Essentially, they could use a trusted domain name as a front for their true destination.
This is actually what makes domain fronting detection and blocking difficult. The good news anyway is that there are still clever ways to prevent domain fronting attack.
In this comprehensive domain fronting tutorial, we’ll explain what domain fronting is. We’ll also explain how cybercriminals can exploit it to launch attacks and practical tips for preventing domain fronting attacks.
So, whether you’re a casual internet user or a seasoned cybersecurity professional, this guide is a must-read for you if you want to protect yourself from the dangers of domain fronting. Read on!
Table Of Contents
What is Domain Fronting Attack?
Domain fronting is a technique for accessing blocked or monitored content. This is achieved by disguising it behind legitimate domain names.
When using domain fronting, the user connects to a trusted domain name, like Google.com for, example. The trusted domain name then forwards the user’s traffic to the true destination server.
This makes it difficult for authorities to identify the actual content being accessed, as the traffic appears to be originating from the trusted domain name. Cybercriminals can also exploit domain fronting to hide their malicious activities from detection.
In this case, a good domain fronting example would be the attackers using a legitimate domain name to send data to a command-and-control server. This would make it appear as though the traffic is benign.
This can allow them to evade detection by security measures looking for known malicious domain names. So, really domain fronting detection can be challenging because it can be difficult to distinguish between legitimate and malicious traffic.
However, there are certain telltale signs that may indicate the presence of domain fronting. For example the destination IP address of the traffic not matching the apparent domain name in the network traffic. Or the traffic uses a well-known content delivery network (CDN) or hosting provider, but the domain name in the network traffic does not match the expected domain name for that provider
How Does a Domain Fronting Attack Work?
As earlier explained, a domain fronting attack is a technique attackers use to disguise the true destination of their network traffic. It works by using a front domain allowed by a network’s filtering or firewall rules to reach a target server.
The actual destination server is usually hidden behind the front domain. To carry out a domain fronting attack, an attacker will first identify a front domain allowed by the target network’s firewall or filtering rules.
They would then send network traffic to the front domain. This front domain acts as a proxy and forwards the traffic to the attacker’s actual destination server.
The destination server responds to the request, and the response is sent back to the front domain, which then forwards it to the attacker. This technique can be used to bypass security controls that block traffic to specific domains or IP addresses.
For example, if a company blocks traffic to a known malware domain, an attacker could use domain fronting to bypass the block and reach the malware server. Domain fronting attacks are difficult to detect because they look like legitimate traffic to the front domain. However, there are practical ways to prevent them.
Domain Fronting Example
To put it simply, domain fronting is like pretending to be someone else when you’re actually going somewhere else entirely. Let’s look at some real-life examples of domain fronting attacks that have happened very recently;
In September 2021, Cisco Talos discovered a hacker who used domain fronting with the Cloudflare CDN to redirect a Myanmar government-owned domain to a different server. They did this by launching a Cobalt Strike beacon and modifying the HTTPs requests header to direct traffic to an attacker-controlled host.
Through domain fronting, they were able to make their traffic look like it was coming from a legitimate high-reputation domain hosted behind Cloudflare infrastructure. Also, in 2018, Mandiant, a threat intelligence company, discovered that Russian nation-state attackers APT29 were using domain fronting to gain backdoor access to victim environments.
They used a combination of the Tor network and a domain fronting plugin called “meek” to make it look like their traffic was legitimate. This allowed them to extract data without being detected.
These examples show just how dangerous domain fronting can be. With just this technique, attackers can evade detection and carry out their malicious activities without being detected. That’s why it’s important for organizations to take steps to prevent domain fronting attacks and protect themselves from potential threats.
How to Prevent Domain fronting Attacks
Domain fronting attacks can be a significant threat to online security and privacy. Implementing measures to prevent such attacks can help mitigate the risks they pose and ensure the integrity and availability of online services.
Preventing domain fronting attacks requires a multi-layered approach. This can include both technical controls and user education. Here are some steps that organizations can take to prevent domain fronting attacks:
1. Implementing Zero Trust Security
Zero Trust Security is a fundamental approach for preventing domain fronting attacks. This security framework operates under the assumption that no device or user can be trusted by default.
So, it requires all devices to be authenticated before granting access. The beauty of this approach is that it eliminates the concept of trusted domains, thereby reducing the attack surface.
With Zero Trust Security, every request is treated as potentially malicious until it is verified as legitimate. With Zero Trust Security, organizations can significantly reduce their risk of being compromised by domain fronting attacks, providing a much-needed layer of security against this sophisticated cyber threat.
2. Prevent Domain Fronting by Eliminating Dangling DNS Entries
Dangling DNS entries are one of the easiest ways for attackers to carry out domain fronting attacks. They are basically DNS records that point to unassigned or non-existent IP addresses and can be easily exploited by cybercriminals.
To minimize the risk of domain fronting attacks, it’s important to review DNS records regularly. During the reviews, be sure to remove any that are no longer needed or point to non-existent IP addresses.
This way, you can reduce the attack surface and prevent attackers from leveraging this weakness to carry out domain fronting attacks. This simple step can go a long way in protecting your organization from the devastating effects of these attacks.
3. Use Security Certificate to Avoid Domain Fronting Attack
SSL/TLS certificates help to establish a secure connection between servers and clients. This helps reduce the risk of man-in-the-middle attacks that can be used to carry out domain fronting. Therefore, makes it more difficult for them to use domain fronting to evade detection and carry out malicious activities.
In case of software or application security Code signing certificate is a critical security measure that adds a digital signature to software. The aim usually is to confirm its authenticity and prevent tampering during transmission.
By adopting code signing, you can help prevent domain-fronting attacks by establishing a chain of trust among your domain and resources in DNS records. Also, by signing your domain and resources with digital signatures, you can showcase their integrity and ensure that the system does not process or validate any unauthorized resources or commands. Code signing is an essential component of a comprehensive security strategy that can help you safeguard against the growing threat of domain-fronting attacks.
4. Installing a Proxy Server to Monitor Traffic
If you’re serious about preventing domain fronting attacks, installing a proxy server is an effective way to monitor traffic and detect any malicious activity. A proxy server acts as an intermediary between the user and the internet, allowing it to examine incoming and outgoing traffic for any suspicious requests.
Organizations can automatically block requests at the proxy server level by setting up rules that flag requests attempting to use domain fronting. This allows organizations to detect and respond to attacks in real time before they reach their intended targets. Furthermore, proxy servers can also help organizations identify the source of the attack, enabling them to take further preventative measures.
In Closing
Domain fronting attacks can be incredibly devastating for organizations. Not only can they steal data and compromise sensitive information, but they can also use your systems to launch further attacks on other organizations.
The worst part is that domain fronting attacks can be difficult to detect and prevent, which makes them even more dangerous. That said, the best course of action is to take steps to prevent domain fronting attacks to protect your organization from the devastating consequences of a domain fronting attack. Start now.