TROJ_PIDIEF.UJ

October 18, 2012
 Analysis by: Mark Joseph Manahan
 ALIASES:

Exploit:Win32/Pdfjsc.ADQ (Microsoft), JS/Exploit.Pdfka.PTI trojan (Eset), Troj/PDFJs-ABB (Sophos)

 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:

13,406 bytes

File Type:

PDF

Memory Resident:

No

Initial Samples Received Date:

16 Oct 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://11.{BLOCKED}dates.com/links/leading_weird_checks.php?eoqahs=3303023302&kdeolbxg=0834050a080937370607&ytexi=03&uwz=zshrvx&xwxqxl=styxiklb

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:

It executes the downloaded file through the following command regsvr32 -s %User Temp%\wpbt0.dll. As a result, the malicious routines of the downloaded file are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.464.06

FIRST VSAPI PATTERN DATE:

17 Oct 2012

VSAPI OPR PATTERN File:

9.465.00

VSAPI OPR PATTERN Date:

17 Oct 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

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\wpbt0.dll

Step 3

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


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