Backdoor:Win32/Sdbot.SM 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.
Installation
When executed, Backdoor:Win32/Sdbot.SM copies itself to <system folder>\sdkcore.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: "SDK Core Component"
With data: "sdkcore.exe"
To subkey: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Adds value: "SDK Core Component"
With data: "sdkcore.exe"
To subkey: HKCU\Software\Microsoft\windows\currentversion\run
The malware creates the following files on an affected computer:
Payload
Terminates processes
Backdoor:Win32/Sdbot.SM terminates a list of specified processes, including those related to particular security applications, should they be running on an affected computer. Backdoor:Win32/Sdbot.SM attempts to terminate the following processes (for example):
- _avpm.exe
- antivirus.exe
- AUPDATE.EXE
- AVGW.EXE
- avp.exe
- avp32.exe
- avpcc.exe
- blackice.exe
- DRWEB32.EXE
- fsav.exe
- NAVW32.exe
- NOD32.EXE
- PERSFW.EXE
- SCAN32.exe
- ZONEALARM.EXE
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 grape.niteangel.info via TCP port 8000, 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 e74db1b7c311aeb8b3adfab130420fb554097287.
