W32/Sdbot-SK

Please follow the instructions for removing worms.

You will also need to edit the following registry entries, if they are present. Please read the warning about editing the registry.

At the taskbar, click Start|Run. Type 'Regedit' and press Return. The registry editor opens.

Before you edit the registry, you should make a backup. On the 'Registry' menu, click 'Export Registry File'. In the 'Export range' panel, click 'All', then save your registry as Backup.

Locate the HKEY_LOCAL_MACHINE entries:

HKLM\Software\Microsoft\Windows\CurrentVersion\Run

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices

and remove any reference to any file you deleted.

Each user has a registry area named HKEY_USERS\[code number indicating user]\. For each user locate the entry:

HKU\[code number]\Software\Microsoft\Windows\
CurrentVersion\Run\

and remove any reference to any file you deleted.

Close the registry editor.

W32/Sdbot-SK is a Windows worm that contains backdoor functions that allow unauthorised remote access to the infected computer via IRC channels while running in the background.

When run W32/Sdbot-SK copies itself to the Windows system folder as Xfsa.exe.

The worm also creates the following registry entries so that it is able to run on computer logon:

HKLM\Software\Microsoft\Windows\CurrentVersion\RunServices
Depassx
Xfsa.exe

HKLM\Software\Microsoft\Windows\CurrentVersion\Run
Depassx
Xfsa.exe

HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Depassx
Xfsa.exe

W32/Sdbot-SK can also be dropped by another Windows Trojan, Troj/Multi-BF, which persists as the filename respond.exe. The worm attempts to spread to network shares using the Trojan filename respond.exe.

W32/Sdbot-SK will try to particpate in denial-of-service (DoS) attacks and download and run files from the internet when instructed to do so by a remote attacker.