HTML_DLOADER.BC

October 09, 2012
 Analysis by: Rhena Inocencio
 ALIASES:

Troj/ExpJS-GD (Sophos)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Hosted on websites

This Trojan may be hosted on a website and run when a user accesses the said website.

It downloads a file from a certain URL then renames it before storing it in the affected system. It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It takes advantage of certain vulnerabilities. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

7,575 bytes

File Type:

HTML, HTM

Initial Samples Received Date:

26 Sep 2012

Payload:

Downloads files, Compromises system security

Arrival Details

This Trojan may be hosted on a website and run when a user accesses the said website.

Download Routine

This Trojan downloads files from the following URLs then renames them before storage in the affected system:

  • http://{BLOCKED}onsmetasearching.net/zXShly?SRUM=7&fRHf=1121

It saves the files it downloads using the following names:

  • %Current Folder%\QNjnEo9.exe

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This Trojan takes advantage of the following vulnerabilities:

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.424.05

FIRST VSAPI PATTERN DATE:

27 Sep 2012

VSAPI OPR PATTERN File:

9.425.00

VSAPI OPR PATTERN Date:

27 Sep 2012

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

Close all opened browser windows

Step 3

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.
  • %Current Folder%\QNjnEo9.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as HTML_DLOADER.BC. 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 5

Download and apply this security patch Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


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