IRC - secuguru/security-terms GitHub Wiki

IRC (Internet Relay Chat) is a text-based communication protocol that allows users to join channels (chat rooms) and communicate in real-time. It was originally developed for group communication but can also support private messaging, file sharing, and multi-channel chats. IRC operates over the internet, typically using TCP on port 6667, but can also use encrypted connections through SSL/TLS (usually on port 6697).

How IRC Works:

  • Channels: Users join specific chat rooms called channels (e.g., #channelname), where they can communicate with others in real time.
  • Servers and Clients: IRC operates using a client-server model, where users connect to an IRC server via an IRC client. Multiple servers can be interconnected in networks, allowing for a broad, distributed communication system.
  • Commands: Users interact with the system using commands such as /join #channel to enter a channel or /msg user to send a private message.

Use by Hackers (Botnets):

IRC has historically been exploited by hackers for nefarious activities, including the management of botnets.

  1. Botnets:
  • A botnet is a network of compromised devices (bots) that can be controlled remotely by an attacker. Hackers infect devices with malware, turning them into bots that can perform coordinated attacks, such as DDoS (Distributed Denial of Service) attacks or spamming campaigns.
  • IRC-based botnets: Hackers use IRC as a command-and-control (C2) channel for managing botnets. The bot-infected devices connect to a specific IRC server and join a hidden channel controlled by the attacker.
  • Once connected, the attacker can issue commands through the IRC channel to all bots simultaneously, instructing them to launch attacks, download additional malware, or steal data.
  1. Anonymity:
  • IRC can be used over the Tor network or with proxies, allowing hackers to remain anonymous and making it difficult for authorities to trace their activities.
  • IRC’s simplicity and the ability to host servers with relative anonymity make it an attractive platform for cybercriminals.
  1. Example of IRC Botnet Control:
  • A hacker creates a malware strain that infects devices, turning them into bots.
  • These bots are programmed to automatically connect to an IRC server, join a secret channel, and await commands.
  • The hacker, from the IRC server, can issue commands to all connected bots to perform attacks or retrieve stolen data.

Why Hackers Use IRC:

  • Real-time Control: IRC allows for real-time communication, making it efficient for coordinating fast-moving attacks like DDoS.
  • Simple and Lightweight: The protocol is simple and lightweight, allowing it to operate even on low-resource devices or compromised systems.
  • Widely Available and Easy to Set Up: IRC servers are easy to deploy, and there are many publicly available IRC networks, providing flexibility for attackers.

Summary:

  • IRC is a real-time communication protocol, originally used for group chats and file sharing.
  • Hackers leverage IRC to manage botnets, using it as a command-and-control channel to coordinate compromised devices for attacks.
  • The anonymous nature of IRC, especially when used with tools like Tor, makes it a favored platform for cybercriminal activities.