JS_LOADER.WRG

 Analysis by: Roland Marco Dela Paz

 ALIASES:

Exploit.JS.CVE-2010-0806.bb (Kaspersky); Exploit.JS.CVE-2010-0806.K (F-Secure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet


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

  TECHNICAL DETAILS

File Size:

9,126 bytes

File Type:

HTML, HTM

Memory Resident:

No

Initial Samples Received Date:

25 May 2012

Payload:

Downloads files

Arrival Details

This Trojan may be downloaded from the following remote sites:

  • http://{BLOCKED}.{BLOCKED}.205.102:8888/sdk.html
  • http://{BLOCKED}.{BLOCKED}.205.102:8888/ddk.html

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}.{BLOCKED}.205.102:8888/sdk.js - JavaScript component
  • http://{BLOCKED}.{BLOCKED}.205.102:8888/cx.exe - detected as BKDR_MORIX.WRG

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

  • Microsoft Internet Explorer Invalid Pointer Reference Remote Code Execution

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

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.137.01

FIRST VSAPI PATTERN DATE:

25 May 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 JS_LOADER.WRG

    • BKDR_MORIX.WRG

Step 3

Close all opened browser windows

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_LOADER.WRG. 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. http://support.microsoft.com/kb/981374


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