Analysis by: Kathleen Notario

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • 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 takes advantage of certain vulnerabilities.

  TECHNICAL DETAILS

File Size: 230,037 bytes
File Type: PDF
Memory Resident: No
Initial Samples Received Date: 26 Aug 2010
Payload: Drops files

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.

Other Details

Based on analysis of the codes, it has the following capabilities:

  • This specially-crafted .PDF file exploits vulnerabilities related to the following Adobe Reader JavaScript functions to drop another malicious file:
    • Collab.getIcon
    • Collab.collectEmailInfo
    • Doc.media.newPlayer
  • After succesfully exploiting the vulnerabilities, it drops and executes the following malicious files:
    • %User Temp%\update.exe - detected as TROJ_DLOADR.AVR
    • %Windows%\ntshrui.dll - detected as TROJ_DLLHJACK.A

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It takes advantage of the following vulnerabilities:

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.408.17
FIRST VSAPI PATTERN DATE: 26 Aug 2010
VSAPI OPR PATTERN File: 7.409.00
VSAPI OPR PATTERN Date: 26 Aug 2010

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.WLB

    TROJ_DLOADR.AVR
    TROJ_DLLHJACK.A

Step 3

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