Backdoor:Win32/Sdbot.OJ

Backdoor:Win32/Sdbot.OJ is a member of Win32/Sdbot - a large family of IRC-controlled backdoors that allow unauthorized access and control of an affected computer. Using this backdoor, an attacker can perform a large number of different actions on an affected computer, including downloading and executing arbitrary files, stealing sensitive information and spreading to other computers using various methods.

When executed, Backdoor:Win32/Sdbot.OJ copies itself to <system folder>\scvsrv32.exe.

Note: <system folder> refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the System folder for Windows 2000 and NT is C:\Winnt\System32; and for XP, Vista, and 7 is C:\Windows\System32.

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

Adds value: "Scvsrv32"
With data: "scvsrv32.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Backdoor:Win32/Sdbot.OJ modifies the Windows Hosts file. The local Hosts file overrides the DNS resolution of a website URL to a particular IP address. Malicious software may make modifications to the Hosts file in order to redirect specified URLs to different IP addresses. Malware often modifies an affected computer's Hosts file in order to stop users from accessing websites associated with particular security-related applications (such as antivirus for example).

At the time of publication, we observed:

Terminates processes

The malware terminates a list of specified processes, including those related to particular security applications, should they be running on an affected computer. Backdoor:Win32/Sdbot.OJ attempts to terminate the following processes (for example):

Note: This list of processes was compiled after observing this behavior in our analysis systems. This list should serve as an example of this behavior only as it may not prove exhaustive on every affected system.

Allows backdoor access and control

The malware attempts to connect to an IRC server at test.f34r.biz via TCP port 8002, 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:

This malware description was produced and published using our automated analysis system's examination of file SHA1 FF34648E5F3221A5F2CE63320555345A9AEF5BA5.