Backdoor:W32/SdBot.CNG

Classification

Category :

Malware

Type :

Backdoor

Aliases :

Virus.Win32.Virut, Backdoor.Generic.178032, Worm:Win32/Neeris.AN (Microsoft) , W32/Virut.gen.A (McAfee)

Summary

A remote administration tool (RAT) that bypasses the security features of a program, computer or network to give unauthorized access or control to its user.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Backdoor:W32/SdBot.CNG is a backdoor program that can be controlled by an attacker through an Internet Relay Chat (IRC) channel. The program itself is usually sized around 28 to 55 kB.

Distribution

SdBot.CNG is propagated through multiple vectors:

  • Removable media such as USB thumb drives
  • Instant Messaging (IM) networks (e.g., AIM, MSN, ICQ and Triton)
  • Network shares
  • Peer-to-Peer (P2P) networks (e.g., Edonkey2000, Morpheus, KAZAA, LimeWire, BearShare and Grokster) via the application's shared folders

Installation

During installation, SdBot.CNG creates a copy of itself in one of these folders:

  • %windir%system\VMwareservice.exe
  • %windir%system32\csrsc.exe

Activity

While active, the backdoor has the following functionalities:

  • Perform SYN Floods
  • Perform Distributed Denial of Service (DDoS) attacks
  • View MSN, AIM and Triton threads
  • Propagate via AIM, MSN and Triton
  • Download files
  • Update itself
  • Steal passwords from Protected Storage
  • View and create processes
  • Visit user defined websites
  • Perform shell executions

SdBot.CNG is also able to detect applications or services such as VMware, Nepenthes, sandboxes and honeypots.

Registry

The backdoor program creates on of the following Registry keys in order to automatically execute the copy of itself saved in the Windows directory:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VMwareService = "VMwareService.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\VMwareService = "VMwareService.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinSpoolSvc = "csrsc.exe"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentSet001\Services\WinSpoolSvc = "csrsc.exe"

It also creates the following Autorun.inf to facilitate its propagation on removal media such as USB thumb drives:

  • [autorun] open = RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe icon=%SystemRoot%\system32\SHELL32.dll,4 action=Open folder to view files
  • [autorun] open = RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe icon=%SystemRoot%\system32\SHELL32.dll,4 action=Open folder to view files shell\open=Open shell\open\command=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\autorunme.exe shell\open\default=1