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

  TECHNICAL DETAILS

File Size: 109,640 bytes
File Type: XLS
Memory Resident: No
Initial Samples Received Date: 03 Sep 2010
Payload: Drops files

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\alg.exe - detected as BKDR_SCROG.OK
  • %User Temp%\EyAƒœEEEAr_,O.xls - non-malicious XLS file

(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 the following software vulnerabilities to drop malicious files:

  • (MS09-067) Vulnerabilities in Microsoft Office Excel Could Allow Remote Code Execution (972652)

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: 8.900
FIRST VSAPI PATTERN FILE: 7.434.10
FIRST VSAPI PATTERN DATE: 03 Sep 2010
VSAPI OPR PATTERN File: 7.435.00
VSAPI OPR PATTERN Date: 03 Sep 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_DROPPER.QUZ

    BKDR_SCROG.OK

Step 3

Search and delete this file

[ 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%\EyAƒœEEEAr_,O.xls

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPER.QUZ. 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. Microsoft Security Bulletin MS09-067


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