Modified by: Cris Nowell Pantanilla
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 134,656 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 17 Jul 2012

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 copies of itself into the affected system:

  • %User Profile%\Application Data\bcmig.dll

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
bcmig = "rundll32.exe "%User Profile%\Application Data\bcmig.dll",CommitTransaction

Download Routine

This Trojan accesses the following websites to download files:

  • http://megaupload.com/file/id={BLOCKED}LbMAXCPkE0sTBcAeGtxfHWCTGN1cEkzWGtxXFUGAQKUkSInG5fNBwAAAAAAATRW&rt=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.200
VSAPI OPR PATTERN File: 9.267.00
VSAPI OPR PATTERN Date: 17 Jul 2012

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • bcmig = ""rundll32.exe "%User Profile%\Application Data\bcmig.dll",CommitTransaction"

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_MEDFOS.SMJ. 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.


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