This threat may make lasting changes to an affected system's configuration that will NOT be restored by detecting and removing this threat. For more information on returning an affected system to its pre-infected state, please see the following information:
Disable Autorun functionality
Backdoor:Win32/IRCbot.FH attempts to spread via removable drives on computers that support Autorun functionality. This is a particularly common method of spreading for many current malware families. For information on disabling Autorun functionality, please see the following article: http://support.microsoft.com/kb/967715/
Backdoor:Win32/IRCbot.FH 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.
When executed, Backdoor:Win32/IRCbot.FH copies itself to c:\documents and settings\administrator\application data\microsoft\svchost.exe.
The malware modifies the following registry entries to ensure that its copy executes at each Windows start:
Adds value: "Startup" With data: "c:\documents and settings\administrator\application data\microsoft\svchost.exe" To subkey: HKCU\Software\Microsoft\windows\currentversion\run
Backdoor:Win32/IRCbot.FH may create the following files on targeted drives when spreading:
It also places an autorun.inf file in the root directory of the targeted drive. Such autorun.inf files contain execution instructions for the operating system, so that when the removable drive is accessed from another computer supporting the Autorun feature, the malware is launched automatically.
Note: This worm was observed to write an executable and create an autorun.inf file on a targeted drive in our automated testing environment. This is particularly common malware behavior, generally utilized in order to spread malware from computer to computer.
It should also be noted that autorun.inf files on their own are not necessarily a sign of infection, as they are used by legitimate programs and installation CDs.
Allows backdoor access and control
Backdoor:Win32/IRCbot.FH allows unauthorized access and control of an affected computer. An attacker can perform any number of different actions on an affected computer using Backdoor:Win32/IRCbot.FH. This could include, but is not limited to, the following actions:
Download and execute arbitrary files
Spread to other computers using various methods of propagation
Log keystrokes or steal sensitive data
Modify system settings
Run or terminate applications
This malware description was produced and published using our automated analysis system's examination of file SHA1 10ae97b3fd01057cab0b036e9203adffdb35cfed.