Analysis by: rolandde

ALIASES:

ExploitWF/CVE-2011-0611.O (Microsoft); Exploit.SWF.CVE-2011-0611.q (Kaspersky)

 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

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

This Trojan arrives as attachment to mass-mailed email messages.

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: 146,448 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 19 May 2011

Arrival Details

This Trojan arrives as attachment to mass-mailed email messages.

Installation

This Trojan drops the following files:

  • %User Temp%\scvhost.exe - detected as BKDR_SVNLOOC.A

(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:

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

NOTES:

In order to hide its malicious routines from the user, it drops the following non-malicious .DOC file:

  • %User Temp%\AAAA

It then replaces itself with the said .DOC file and opens it.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.200.05
FIRST VSAPI PATTERN DATE: 03 Jun 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_MDROP.SMCM

    BKDR_SVNLOOC.A

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%\AAAA

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_MDROP.SMCM . 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://www.adobe.com/support/security/bulletins/apsb11-07.html


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