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Proxy-Agent.ar

This page shows details and results of our analysis on the malware Proxy-Agent.ar

Threat Detail

Malware Type: Trojan

Malware Sub-type: Proxy

Discovery Date: 2006-02-27

Next Steps:

Overview

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.


Minimum DAT

4706 (2006-02-27)

Updated DAT

4804 (2006-07-11)

 Minimum Engine

5.1.00

File Length

varies

 Description Added

2006-02-27

Description Modified

2006-03-02

Malware Proliferation

Characteristics

This detection is for malware intended to serve as a proxy on the victim machine. Once running the infected host may be used as an email relay, which is likely to be used for routing spam messages.

Upon execution, the trojan drops the following files:

  • %WINDIR%\system32\ssldr32.dll ( 12085 bytes )
  • %WINDIR%\system32\wancp.dll ( 44516 bytes )

The following registry keys are created:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\ssldr
    "Asynchronous" = 0
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\ssldr
    "DLLName" = "ssldr32.dll"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\ssldr
    "Impersonate" = "0"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\ssldr
    "Logoff" ="StopProcessAtWinLogoff"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\ssldr
    "Logon" = "StartProcessAtWinLogon"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\wancp
    "Asynchronous" ="0"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\wancp
    "DLLName" = "wancp.dll"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\wancp
    "Impersonate" = "0"
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\wancp
    "Logoff" = StopProcessAtWinLogoff
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify\wancp
    "Logon" = StartProcessAtWinLogon

The trojan attempts to connect to the remote host at port 12157 and 12156. It also connects to the infected machine's default smtp server to relay mail messages.

Symptoms

  • Unexpected smtp connections
  • Presence of the mentioned registry keys and files

Method of Infection

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, email, etc.

Removal

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

But in some particular cases, the following steps need to be taken.

Please go to the Microsoft Recovery Console and restore a clean MBR.

On Windows XP:

  • Insert the Windows XP CD into the CD-ROM drive and restart the computer.
  • When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
  • Select the Windows installation that is compromised and provide the administrator password.
  • Issue 'fixmbr' command to restore the Master Boot Record
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.


On Windows Vista and 7:

  • Insert the Windows CD into the CD-ROM drive and restart the computer.
  • Click on "Repair Your Computer".
  • When the System Recovery Options dialog comes up, choose the Command Prompt.
  • Issue 'bootrec /fixmbr' command to restore the Master Boot Record.
  • Follow onscreen instructions.
  • Reset and remove the CD from CD-ROM drive.

Variants

United States - English