TROJ_PIDIEF.NTB

October 09, 2012
 Analysis by: Rhena Inocencio
 ALIASES:

Exploit:Win32/Pdfjsc.ADE (Microsoft), JS/Exploit.Pdfka.PSK trojan (ESET)

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

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

14,752 bytes

File Type:

PDF

Initial Samples Received Date:

28 Sep 2012

Arrival Details

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

Installation

This Trojan drops the following files:

  • %User Temp%\A9R31CA.tmp

(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.)

Download Routine

This Trojan downloads the file from the following URL and renames the file when stored in the affected system:

  • http://{BLOCKED}y.{BLOCKED}3.com/external/expression-games-affected.php?yyuby=080a370938&uwxah=08020234070305093308&cbrbt=03&mmwcl=tea&nih=uok

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.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.426.05

FIRST VSAPI PATTERN DATE:

28 Sep 2012

VSAPI OPR PATTERN File:

9.427.00

VSAPI OPR PATTERN Date:

29 Sep 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%\A9R31CA.tmp
  • %User Temp%\wpbt0.dll

Step 3

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