Analysis by: Kathleen Notario
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor drops a file. If unsuccessful, it drops the file as %Windows%\msacm32.dll also detected as BKDR_VILSEL.RIA instead. The said dropped file accesses a remote site.

This backdoor 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: 18,944 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 29 Dec 2011

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_PIDIEF.ARJO

Backdoor Routine

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

  • Perform shell command
  • Download and execute files
  • Send system information (IP address, user name, operating system)

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

  • {BLOCKED}miki.myfw.us

NOTES:

It drops the following file:

  • %System%\browseui.dll - also detected as BKDR_VILSEL.RIA

If unsuccessful, it drops the file as %Windows%\msacm32.dll also detected as BKDR_VILSEL.RIA instead. The said dropped file is the one accessing the remote site.

  SOLUTION

Minimum Scan Engine: 9.200

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 the malware/grayware file that dropped/downloaded BKDR_VILSEL.RIA

     
    • TROJ_PIDIEF.ARJO

Step 3

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