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Backdoor:Win32/IRCbot.EW


Backdoor:Win32/IRCbot.EW is a member of Win32/IRCbot - a broad family of backdoor trojans that allows unauthorized access and control of an affected computer by a remote attacker via IRC.


What to do now

To detect and remove this threat and other malicious software that may have been installed in your computer, run a full-system scan with an up-to-date antivirus product such as the following: For more information about using antivirus software, see http://www.microsoft.com/windows/antivirus-partners/.

Threat behavior

Backdoor:Win32/IRCbot.EW is a member of Win32/IRCbot - a broad family of backdoor trojans that allows unauthorized access and control of an affected computer by a remote attacker via IRC.
Installation
When executed, Backdoor:Win32/IRCbot.EW copies itself to c:\documents and settings\administrator\local settings\temp\lsass.exe.

The malware modifies the following registry entries to ensure that its copy executes at each Windows start:

Adds value: "Windows Firewall"
With data: "c:\documents and settings\administrator\local settings\temp\lsass.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Adds value: "Windows Firewall"
With data: "c:\documents and settings\administrator\local settings\temp\lsass.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run

The malware creates the following files on an affected computer:

  • c:\documents and settings\administrator\local settings\temp\google_cache114.tmp
Payload
Allows backdoor access and control
Backdoor:Win32/IRCbot.EW attempts to connect to an IRC server at 92.241.174.17 via TCP port 6667, join a channel and wait for commands. Using this backdoor, an attacker can perform a number of actions on an affected computer. For example, an attacker may be able to perform the following actions:

  • Download and execute arbitrary files
  • Upload files
  • Spread to other computers using various methods of propagation
  • Log keystrokes or steal sensitive data
  • Modify system settings
  • Run or terminate applications
  • Delete files

This malware description was produced and published using our automated analysis system's examination of file SHA1 ee8d329d2970979d1f9ebf4d4764ebaa6341180c.

Symptoms

System changes
The following system changes may indicate the presence of this malware:

  • The presence of the following files:
  • c:\documents and settings\administrator\local settings\temp\google_cache114.tmp
    c:\documents and settings\administrator\local settings\temp\lsass.exe

  • The presence of the following registry modifications:
  • Adds value: "Windows Firewall"
    With data: "c:\documents and settings\administrator\local settings\temp\lsass.exe"
    To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    Adds value: "Windows Firewall"
    With data: "c:\documents and settings\administrator\local settings\temp\lsass.exe"
    To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Run


Prevention


Alert level: Severe
First detected by definition: 1.95.1867.0
Latest detected by definition: 1.183.2388.0 and higher
First detected on: Dec 15, 2010
This entry was first published on: Dec 24, 2010
This entry was updated on: Apr 17, 2011

This threat is also detected as:
  • Suspect-AC!E30DD121029B (McAfee)
  • WORM_PUSHBOT.SMA (Trend Micro)
  • Trojan.Win32.Swisyn.ajmj (Kaspersky)