Analysis by: Kathleen Notario
ALIASES:

Exploit:Win32/CVE-2009-3129 (Microsoft); Troj/DocDrop-AB (Sophos)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Spammed via email

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It does not have any propagation routine.

It does not have any backdoor routine.

It takes advantage of software vulnerabilities in certain software to drop malicious files. It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 92,026 bytes
File Type: XLS
Initial Samples Received Date: 23 Mar 2012
Payload: Drops files

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops the following non-malicious file:

  • %User Temp%\Microsoft Excel.xls

(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.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\apimgr.exe - detected as BKDR_GENOME.CI

(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 takes advantage of unknown vulnerabilities in the following software to drop malicious files:

  • Excel Featheader Record Memory Corruption Vulnerability

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

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

More information on this vulnerability can be found below:

NOTES:

It does not have rootkit capabilities.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.860.03
FIRST VSAPI PATTERN DATE: 23 Mar 2012
VSAPI OPR PATTERN File: 8.861.00
VSAPI OPR PATTERN Date: 24 Mar 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

Remove malware files dropped/downloaded by TROJ_SHELLCOD.CI

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.
  • %User Temp%\Microsoft Excel.xls

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_SHELLCOD.CI. 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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