Cybersecurity ProxyChains: A Mask of Anonymity

Source: Dev.to

ProxyChains: What Are They?

ProxyChains is a UNIX/Linux utility that forces any TCP connection made by a specific application to go through a series of proxies (e.g., SOCKS or HTTP). This enables you to hide your IP address and send your connection via multiple middlemen before it reaches the destination server, increasing anonymity and making it harder to determine the request’s true source.

The Operation of ProxyChains

ProxyChains works by modifying the dynamic linker settings of dynamically linked programs. It intercepts outgoing TCP connections and routes them through the configured proxy chain. The typical flow is:

1. Application initiates a TCP connection.
2. ProxyChains intercepts the request.
3. The request is forwarded through the proxies in the defined order.
4. The final destination receives the traffic from the last proxy.

When combined with Tor (The Onion Router), the IP address is not only hidden but also redirected through a dispersed network of volunteer‑operated relays, further enhancing anonymity.

Real‑World Use: Case Study of Russian Military Cyber Actors (2024)

According to a joint advisory released by CISA, Russian military cyber actors used ProxyChains together with tools such as CrackMapExec to avoid detection while automating assessments of large Active Directory environments. By chaining proxies, the threat actors were able to:

• Spoof internal victim IP addresses.
• Move laterally across networks covertly.

This incident illustrates how adversaries employ proxy chaining to gain deeper access to critical infrastructure while evading detection.

Example Configuration

The ProxyChains configuration file is typically located at /etc/proxychains.conf. Below is a basic example:

# /etc/proxychains.conf
[ProxyList]
# format:  type  ip  port
socks5  127.0.0.1 9050
http    192.168.1.100 8080
socks4  10.0.0.5 1080

Chaining Methods

• Dynamic Chain – Tries proxies in the order listed, skipping any that fail.
• Strict Chain – Must use proxies in the exact order; aborts if one fails.
• Random – Selects a random proxy for each connection.

Note: ProxyChains is fully supported only on Linux distributions.

Hands‑On with ProxyChains

Using Nmap through ProxyChains

proxychains nmap -sT -Pn scanme.nmap.org

Running Firefox through ProxyChains

proxychains firefox

Why Use ProxyChains?

• Anonymity: Conceals your original IP address.
• Bypass IP‑based restrictions: Evade IP filtering and geo‑blocking.
• Evade detection: Helps attackers and pentesters remain hidden.
• Chaining with Tor: Increases anonymity by routing through the Tor network.

Limitations

• Works only with TCP traffic.
• Can significantly slow down connections.
• Requires manual updates of proxy lists.
• Incompatible with statically compiled binaries.

Conclusion

ProxyChains is an effective addition to any cybersecurity toolkit when stealth and anonymity are crucial. Whether you are a cyber researcher, pentester, or red‑team member, understanding how to use ProxyChains can provide insight into adversarial tactics and help you develop countermeasures.

Remain covert. Remain safe.

References

• CISA Advisory on Russian Cyber Activity
• The Evolution and Abuse of Proxy Networks (link not provided)

The information and methods presented above are solely for educational purposes. Unauthorized hacking is illegal. The author and publisher are not liable for any misuse of this content.