Analysis by: Karl Dominguez


Windows 2000, Windows XP, Windows Server 2003


  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes


This Trojan may be dropped by other malware.


File Size: 123,127 bytes
File Type: PDF
Initial Samples Received Date: 16 Sep 2011

Arrival Details

This Trojan may be dropped by the following malware:



This Trojan drops the following files:

  • %Current%\iso88591 - non-malicious component file
  • %User Temp%\110830g.pdf - non-malicious PDF opened by the malware to hide its malicious routine
  • %User Temp%\Acrobat.exe - TROJ_DROPPER.QUB

(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 the following software vulnerabilities to drop malicious files:

Other Details

More information on this vulnerability can be found below:


Minimum Scan Engine: 9.200
VSAPI OPR PATTERN File: 8.435.00
VSAPI OPR PATTERN Date: 18 Sep 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 the malware/grayware file that dropped/downloaded TROJ_PIDIEF.FUA

Step 3

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.
  • %Current%\iso88591
  • %User Temp%\110830g.pdf

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_PIDIEF.FUA. 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 5

Download and apply this security patch 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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