Windows 2003/XP/2000/NT/ME/98/95

IRCBot.YH is a backdoor that allows hackers to gain remote access to the affected computer in order to carry out actions that compromise user confidentiality and impede the tasks performed on the computer.

It reduces the security level of the computer: it terminates processes belonging to security tools, such as antivirus programs and firewalls, leaving the computer defenseless against attacks from other malware; it opens one or more ports to allow remote access to the computer and takes action that compromises user confidentiality; it awaits remote-control orders received through IRC; it changes system permissions, decreasing the security level.

IRCBot.YH prevents access from programs to websites of several companies related with security tools (antivirus programs, firewalls, etc.).

It uses stealth techniques to avoid being detected by the user:

• It terminates processes corresponding to several security tools, such as antivirus programs and firewalls, to prevent detection.

It uses several methods in order to avoid detection by antivirus companies:

• It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.

IRCBot.YH uses the following propagation or distribution methods:

• Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
• Via Internet, exploiting remote vulnerabilities: attacking random IP addresses, in which it tries to insert a copy of itself by exploiting one or more vulnerabilities.
• IRC: It sends a copy of itself to all users connected to the channel to which the infected user is connected.