Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be dropped by other malware.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 108,544 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 09 Feb 2014
Payload: Compromises system security, Connects to URLs/IPs

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be dropped by the following malware:

  • TROJ_ARTIEF.VDY

Installation

This backdoor drops the following copies of itself into the affected system:

  • %Windows%\msacm32.drv

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

It injects itself into the following processes running in the affected system's memory:

  • explorer.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Y123YYY

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • getdrivelist
  • getfilelist
  • delfile
  • newupload
  • newdownload
  • runfile
  • urldownload
  • sleep
  • delay
  • maxblock
  • stop

It connects to the following websites to send and receive information:

  • {BLOCKED}ard.mooo.com

  SOLUTION

Minimum Scan Engine: 9.700

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

Remove the malware/grayware file dropped/downloaded by BKDR_INJECT.VDY

    TROJ_ARTIEF.VDY

Step 3

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_INJECT.VDY. 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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