TROJ_MDROPPR.AI

October 09, 2012
 Analysis by: Karl Dominguez
 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

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

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

  TECHNICAL DETAILS

File Size:

69,645 bytes

File Type:

XLS

Memory Resident:

No

Initial Samples Received Date:

18 Feb 2011

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 files:

  • %User Temp%\{random characters}.tmp - BKDR_SIMBOT.SMXA
  • %User Temp%\tmp.xls – non malicious Excel 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.)

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:

NOTES:

This malware affects the following vulnerable software:

  • Microsoft Office XP SP3
  • Microsoft Office 2003 SP3
  • Microsoft Office 2007 SP1 and SP2

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

7.844.09

FIRST VSAPI PATTERN DATE:

18 Feb 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_MDROPPR.AI

     BKDR_SIMBOT.SMXA

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%\tmp.xls 

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROPPR.AI . 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. http://technet.microsoft.com/en-us/security/bulletin/MS09-067


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