BKDR_HORSMY.BLA

July 09, 2013
 Analysis by: Rika Joi Gregorio
 ALIASES:

TrojanSpy:Win32/Fucobha.A (Microsoft)

 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:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor may be dropped by other malware.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

126,976 bytes

Memory Resident:

Yes

Initial Samples Received Date:

27 Sep 2011

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_ARTIEF.BA

Installation

This backdoor drops the following file(s)/component(s):

  • %Windows%\wdmaud.drv

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

It injects threads into the following normal process(es):

  • Explorer.exe

Download Routine

This backdoor accesses the following websites to download files:

  • http://www.{BLOCKED}bit.com/tt/upload.aspx?filepath=info&filename=000C29B984B4_{IP Address}.jpg
  • http://www.{BLOCKED}bit.com/tt/order/000C29B984B4_{IP Address}.jpg

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.300

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 that dropped/downloaded BKDR_HORSMY.BLA

    TROJ_ARTIEF.BA

Step 3

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_HORSMY.BLA. 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 4

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.  %Windows%\wdmaud.drv


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