IRC

What is IRC?

Internet Relay Chat (IRC) is a real-time messaging protocol created in the late 1980s that allows users to communicate via public channels or private messages. It operates over TCP and follows a client--server model, where users connect to IRC servers (networks) and join channels.

IRC is one of the earliest forms of online chat.

Why IRC matters

IRC remains relevant because it:

• Influenced modern chat and collaboration tools
• Is still used by technical communities and open-source projects
• Appears in cybersecurity contexts (malware command-and-control)
• Represents a common legacy protocol still encountered in networks

Understanding IRC helps assess both collaboration history and security risk.

How IRC works (simplified)

1. A user connects to an IRC server using a client
2. The user joins one or more channels (e.g., #security)
3. Messages are broadcast to all users in the channel
4. Private messages can be sent directly between users

Communication is mostly plaintext unless encrypted tunnels are used.

Core IRC concepts

Key IRC elements include:

• Server / Network -- infrastructure hosting IRC services
• Client -- software used to connect (terminal or GUI)
• Channel -- shared chat room (prefixed with #)
• Nickname (nick) -- user identifier
• Operator (op) -- user with moderation privileges

These concepts define access and moderation.

Common IRC use cases

Historically and currently, IRC is used for:

• Open-source project coordination
• Developer and technical community chats
• Real-time support and discussions
• Lightweight communication over low bandwidth

Its simplicity remains an advantage in constrained environments.

IRC and cybersecurity

In security contexts, IRC is notable because:

• It has been used as a command-and-control (C2) channel by malware
• Traffic may bypass poorly configured firewalls
• Commands can be issued remotely to infected hosts
• Detection is possible through network monitoring

Modern malware has largely moved to HTTP/S and cloud services, but IRC C2 still exists in legacy threats.

Security risks

IRC presents several security concerns:

• Plaintext communication by default
• Lack of built-in authentication
• Susceptibility to impersonation
• Use in botnets and malware control
• Limited logging and auditing

Unrestricted IRC traffic is often blocked in enterprise networks.

IRC vs modern messaging platforms

Aspect	IRC	Modern chat apps
Interface	Text-based	Rich UI
Encryption	Optional / external	Built-in
Identity	Nicknames	Account-based
Moderation	Basic	Advanced
Enterprise use	Limited	Widespread

Modern platforms prioritize security, identity, and compliance.

IRC today

Today, IRC is:

• Mostly used by niche technical communities
• Considered legacy in enterprise environments
• Monitored or restricted for security reasons
• Occasionally encountered in incident investigations

Its footprint is smaller but not extinct.

Common misconceptions

• "IRC is obsolete everywhere"
• "IRC is encrypted by default"
• "IRC is only used by hackers"
• "Blocking IRC breaks nothing"