Proxychains for routing traffic

👉 Overview

👀 What ?

Proxychains is a tool that allows users to route their traffic through a number of proxy servers, which can help increase anonymity and bypass network restrictions.

🧐 Why ?

Understanding Proxychains is essential for maintaining online privacy and security. It can also be a crucial tool for ethical hackers and cybersecurity professionals to test the robustness of network systems.

⛏️ How ?

To use Proxychains, you first need to install it on your system. Then, you configure it by listing the proxies you want your traffic to pass through in the Proxychains configuration file. Finally, you simply prepend the 'proxychains' command to any command you want to route through the proxies.

⏳ When ?

Proxychains has been utilized in the field of cybersecurity since its initial release in 2001. Its use has become more widespread as awareness about online privacy and security has grown.

⚙️ Technical Explanations

Proxychains operates by intercepting the TCP (Transmission Control Protocol) calls that applications make. These calls are responsible for establishing a connection between two hosts over the internet so that data can be sent and received. When a TCP call is made, Proxychains steps in and redirects this call through one or more SOCKS (Socket Secure) or HTTP (Hypertext Transfer Protocol) proxies.

A proxy server is essentially an intermediary which handles requests from clients seeking resources from other servers. When you use a proxy, your request runs through the proxy server first, and only then connects to the website. Consequently, the website sees the proxy, not you.

When Proxychains forces the TCP calls to go through these proxies, it helps obfuscate the origin of the traffic. This means that it hides the original source of the traffic, making it difficult to trace back to the user. This is beneficial in maintaining online privacy as it can prevent third parties from tracking your online activities.

Furthermore, Proxychains can also be used to bypass network restrictions. Some networks may block certain websites or services. By routing your traffic through a proxy, you can access these blocked resources because the network only sees the connection to the proxy, not to the blocked website.

Proxychains is a preloader, meaning it loads itself before loading the desired program. It hooks calls to sockets in dynamically linked programs. In terms of computer programming, a hook is a mechanism by which a function can intercept events or messages meant for another function. This mechanism allows Proxychains to intercept the TCP calls and redirect them through the listed proxies.

Let's say we want to connect to a website (www.example.com) using Proxychains. Here's how we could do it:

1. Installation: Install Proxychains on your system. If you're using a Debian-based Linux distribution, you could use the following command in your terminal:

sudo apt-get install proxychains

1. Configuration: Next, configure Proxychains with your desired proxies. This is done in the Proxychains configuration file, usually located at /etc/proxychains.conf. Here's an example of what your configuration might look like:

# proxychains.conf
strict_chain
proxy_dns
tcp_read_time_out 15000
tcp_connect_time_out 8000
[ProxyList]
socks4  127.0.0.1 9050

In this example, we're using a SOCKS4 proxy running on our local machine (127.0.0.1) at port 9050.

1. Usage: Now, you can use Proxychains to route your traffic through the proxy. To do this, prepend your desired command with proxychains. For example, if we were using curl to connect to www.example.com, we would use the following command:

proxychains curl www.example.com

In this example, the curl command is used to send a request to www.example.com. But because we've prepended proxychains, this request gets routed through our SOCKS4 proxy before reaching www.example.com. This hides our original IP address from the website and allows us to bypass any network restrictions.

Remember, Proxychains is a powerful tool and should be used responsibly. It's important to respect all relevant laws and website terms of service when using it.

🖇️ Références