Analysis by: Cris Nowell Pantanilla

ALIASES:

Exploit:Win32/PDFjsc.VG (Microsoft); Exploit.PDF.AN (F-Secure)

 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

Infection Channel: Spammed via email

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

It does not have any propagation routine.

It takes advantage of software vulnerabilities in certain software to drop malicious files. It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 134,107 bytes
File Type: PDF
Initial Samples Received Date: 13 Jan 2012
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 the following non-malicious file:

  • {malware path}\iso88591
  • %User Temp%\Adobe.pdf

(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.)

Propagation

This Trojan does not have any propagation routine.

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\Winword.exe - TROJ_WIMMIE.C

(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.)

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

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

NOTES:

This Trojan takes advantage of the aforementioned Adobe vulnerabilities. It does this to execute its malicious routines on the affected system.

It does not have rootkit capabilities.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.706.03
FIRST VSAPI PATTERN DATE: 13 Jan 2012
VSAPI OPR PATTERN File: 8.707.00
VSAPI OPR PATTERN Date: 14 Jan 2012

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 files dropped/downloaded by TROJ_PIDIEF.EIJ

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_PIDIEF.EIJ. 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.


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