Backdoor:W32/SdBot.AAY

Classification

Category :

Malware

Type :

Backdoor

Aliases :

Backdoor:W32/SdBot.AAY, Backdoor.Win32.SdBot.aay

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.AAY spreads by exploiting a variety of vulnerabilities and can be controlled by a remote attacker through a password-protected IRC channel.

The backdoor's file is a PE executable about 210 kilobytes long, packed with SVPK file compressor.

Infection

When the backdoor's file is started, it copies itself as 'mssvces.exe' file to Windows System folder and then creates the following startup key value in the Registry:

  • "Shell" = "Explorer.exe mssvces.exe"

Propagation

The bot exploits the following vulnerabilities in order to spread:

  • LSASS (MS04-011) port 445
  • WKSSVC (MS03-049) port 445
  • ASN.1 (MS04-007) ports 80, 139, 445

Activity

When the backdoor is active, it connects to an IRC server, joins a certain channel and acts as a bot there. The backdoor also starts IDENTD server on port 113.

The following IRC server and ports are used by the backdoor:

  • asnpwnz12345.server.us:7645
  • asnpwnz12345.server.us:95644

The backdoor joins the following password-protected IRC channel:

  • #asnpwn

A hacker can send commands to the bots to control infected computers. Several tasks can be performed, including the following:

  • start FTP server
  • perform ping, SYN, ICMP and UDP flood
  • get system information including information about OS, network and drives
  • update the backdoor's file from Internet
  • operate backdoor's bot (nick change, join/part channels, etc.)
  • redirect traffic on certain ports
  • open a URL with default web browser
  • join and spy on certain IRC channels
  • download and execute files
  • manipulate Internet Explorer zone settings
  • scan and exploit computers vulnerable to exploits