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 does not have any propagation routine.

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: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Dec 2011

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_ARTIEF.IXC

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}baba.myfw.us

NOTES:

Propagation

This backdoor does not have any propagation routine.

Rootkit Capabilities

This backdoor does not have rootkit capabilities.

Other Details

This backdoor drops the following file:

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

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

This backdoor does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.670.05
FIRST VSAPI PATTERN DATE: 27 Dec 2011
VSAPI OPR PATTERN File: 8.671.00
VSAPI OPR PATTERN Date: 28 Dec 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 the malware/grayware file that dropped/downloaded BKDR_VILSEL.XA

Step 3

Identify and delete files detected as BKDR_VILSEL.XA using either the Startup Disk or Recovery Console

[ Learn More ]

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_VILSEL.XA. 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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