Analysis by: Sabrina Lei Sioting
ALIASES:

Exploit.RTF.Gen [FSecure]; Exploit.RTF [Ikarus]

 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 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 files it drops, prompting the affected system to exhibit the malicious routines they contain.

  TECHNICAL DETAILS

File Size: 351,780 bytes
File Type: RTF
Memory Resident: No
Initial Samples Received Date: 21 Mar 2012
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 non-malicious file:

  • %User Temp%\temp.rtf

(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 drops the following files:

  • %User Temp%\temp.exe - detected as BKDR_VISEL.FQ

(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:

It executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.854.05
FIRST VSAPI PATTERN DATE: 21 Mar 2012
VSAPI OPR PATTERN File: 8.855.00
VSAPI OPR PATTERN Date: 22 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_ARTIEF.FQ

    BKDR_VISEL.FQ

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_ARTIEF.FQ. 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.  http://technet.microsoft.com/en-us/security/bulletin/MS10-087


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