Analysis by: Karl Dominguez
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

It takes advantage of software vulnerabilities in certain software to drop malicious files.

  TECHNICAL DETAILS

File Size: 490,228 bytes
File Type: PDF
Memory Resident: No
Initial Samples Received Date: 28 Dec 2011
Payload: Drops files

Arrival Details

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

Installation

This Trojan drops and executes the following files:

  • %User Temp%\AdobeARM.dll - TROJ_VILSEL.RIA

(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.)

Dropping Routine

This Trojan takes advantage of unknown vulnerabilities in the following software to drop malicious files:

  • Adobe Reader and Acrobat 10.1.1 and earlier

It takes advantage of the following software vulnerabilities to drop malicious files:

Other Details

For more information on the aforementioned vulnerabilities, please see the following pages:

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.672.02
FIRST VSAPI PATTERN DATE: 28 Dec 2011

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware/grayware files dropped/downloaded by TROJ_PIDIEF.ARJO

    TROJ_VILSEL.RIA

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_PIDIEF.ARJO. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 4

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors. http://www.adobe.com/support/security/bulletins/apsb11-30.html


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