Analysis by: rolandde
ALIASES:

Mal/JSShell-B (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

This malware is an infection vector related to a vulnerability which is triggered when Windows Multimedia Library in Windows Media Player (WMP) fails to handle a specially crafted MIDI file, consequently allowing remote attackers to execute arbitrary code.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

This Trojan executes when a user accesses certain websites where it is hosted.

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

  TECHNICAL DETAILS

File Size: 16,453 bytes
File Type: HTML, HTM
Initial Samples Received Date: 25 Jan 2012
Payload: Downloads files, Connects to URLs/IPs

Arrival Details

This Trojan executes when a user accesses certain websites where it is hosted.

It may be downloaded from the following remote sites:

  • http://{BLOCKED}s.{BLOCKED}p.com/mp.html

Download Routine

This Trojan takes advantage of the following software vulnerabilities to download possibly malicious files:

After successfully exploiting the said vulnerability, this malware connects to the following URLs to possibly download other malicious files:

  • http://{BLOCKED}s.{BLOCKED}p.com/tdc.exe - detected as TROJ_DLOAD.QYUA

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 requires the following additional components to properly run:

  • http://{BLOCKED}s.{BLOCKED}p.com/is.js - detected as JS_EXPLT.QYUA
  • http://{BLOCKED}s.{BLOCKED}p.com/baby.nid - detected as TROJ_MDIEXP.QYUA

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 8.732.07
FIRST VSAPI PATTERN DATE: 26 Jan 2012
VSAPI OPR PATTERN File: 8.733.00
VSAPI OPR PATTERN Date: 26 Jan 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

Remove malware files dropped/downloaded by HTML_EXPLT.QYUA

Step 3

Close all opened browser windows

Step 4

Scan your computer with your Trend Micro product to delete files detected as HTML_EXPLT.QYUA. 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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