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Backdoor:W32/SdBot.AAY

Classification

Category: Malware

Type: Backdoor

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

Summary


A remote administration utility which bypasses normal security mechanisms to secretly control a program, computer or network.

Removal


Automatic action

Based on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the detected program or file, or ask you for a desired action.

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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