Analysis by: Kathleen Notario
ALIASES:

Exploit:Win32/Pdfjsc.gen!A (Microsoft); Exp/20110611-A (Sophos); Exploit/PDF.Gen.B (Panda)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Propagates via software vulnerabilities

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

  TECHNICAL DETAILS

File Size: 138,062 bytes
File Type: PDF
Initial Samples Received Date: 19 Sep 2011
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.

Installation

This Trojan drops the following files:

  • %System Root%\Documents and Settings\All Users\Application Data\google\googleservice.dll - detected as BKDR_ZAPCHAST.QZ
  • %System Root%\All Users\Start Menu\Programs\Startup\googleservice.exe - detected as BKDR_ZAPCHAST.QZ
  • %User Profile%\Application Data\google\googleservice.dll - detected as BKDR_ZAPCHAST.QZ
  • %User Temp%\AdobeARM.dll - detected as BKDR_ZAPCHAST.QZ
  • %User Temp%\googlesetup.dll - detected as BKDR_ZAPCHAST.QZ

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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 creates the following folders:

  • %System Root%\Documents and Settings\All Users\Application Data\google
  • %User Profile%\Application Data\google

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Dropping Routine

This Trojan takes advantage of the following software vulnerabilities to drop malicious files:

  • CVE-2011-0611

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

Other Details

More information on this vulnerability can be found below:

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.438.10
FIRST VSAPI PATTERN DATE: 19 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 malware files dropped/downloaded by TROJ_PIDIEF.EED

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\Documents and Settings\All Users\Application Data\google
  • %User Profile%\Application Data\google

Step 4

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