Threat Description

Backdoor:​W32/IRCBot.ES

Details

Aliases: Backdoor.Win32.IRCBot.es
Category: Malware
Type: BackdoorWorm
Platform: W32

Summary



A remote administration utility that bypasses normal security mechanisms to secretly control a program, computer or network.



Removal



Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see Removal Instructions.

Special Removal Tool

F-Secure provides a special disinfection utility program to eliminate this malware infection. You can download this utility from our ftp or web sites:

  • ftp://ftp.f-secure.com/anti-virus/tools/f-bot.zip
  • http://www.f-secure.com/tools/f-bot.exe
  • ftp://ftp.f-secure.com/anti-virus/tools/f-bot.exe

Disinfection instructions can be found here:

  • ftp://ftp.f-secure.com/anti-virus/tools/f-bot.txt

If the infection is in a local network, please follow the instructions on this webpage:



Technical Details



Backdoor:W32/IRCBot.EX provides unauthorised access to an infected computer and also has the capability to spread to remote computers using the PnP exploit on port 445.

The backdoor's file is a PE executable file about 8 kilobytes long, packed with MEW file compressor and patched with PE_Patch.

This IRC-based backdoor-worm was found on August 15th, 2005 in Finland.

Propagation

The backdoor has the ability to spread to remote computers using the PnP exploit on port 445. Please see the following page for detailed information on the vulnerability:

  • http://www.microsoft.com/technet/security/Bulletin/MS05-039.mspx

Installation

When the backdoor's file is activated on a computer, it copies its file to Windows System folder as MOUSEBM.EXE and then starts the copied file as a service named 'Mouse Button Monitor', described as follows: Enables a computer to maintain synchronization with a PS/2 pointing device. Stopping or disabling this service will result in system instability.

If the backdoor fails to start its service, it tries to inject its code into Explorer.exe process.

Backdoor

When active, the backdoor connects to one of the following servers on port 18067:

  • esxt.is-a-fag.net
  • esxt.legi0n.net

Then backdoor joins an IRC channel called '#p2' using the hardcoded password and creates a bot there. A remote hacker can control a backdoor via a bot that it creates in the '#p2' channel. A hacker can do any of the following:

  • Scan for vulnerable computers and spread to them using PnP exploit
  • Download and run files on an infected computer
  • Find files on local hard disks
  • Perform DDoS (Distributed Denial of Service) attack
  • Perform SYN and UDP flood





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