Analysis by: Mark Joseph Manahan

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: Varies
File Type: PDF
Initial Samples Received Date: 26 Jul 2012

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Download Routine

This Trojan accesses the following websites to download files:

  • http://link.{BLOCKED}t.com/w.php?f=b6863&e=3

It saves the files it downloads using the following names:

  • %User Temp%\wpbt0.dll

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

As of this writing, the said sites are inaccessible.

NOTES:

This Trojan executes the downloaded file using the commandregsvr32 -s %User Temp%\wpbt0.dll. As a result, the malicious routines of the downloaded file are exhibited on the affected system.