Analysis by: Michael Cabel
 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: Dropped by other malware

This JavaScript loads another JavaScript also detected as JS_KOOBFACE.AC. The said file redirects to another URL.

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 455 bytes
File Type: Script
Memory Resident: No
Initial Samples Received Date: 15 May 2012
Payload: Shows advertisements

Arrival Details

This Trojan may be dropped by the following malware:

  • TROJ_KOOBFACE.AC

NOTES:

This JavaScript loads another JavaScript named myscript.js, also detected as JS_KOOBFACE.AC.

The file myscript.js redirects to the following URL:

  • http://www.{BLOCKED}acebook-profile.com/dealer.js

The aforementioned site checks the URL of the page where this malware is hosted if it matches any of the following:

  • amazon
  • bidvert
  • facebook
  • google

If it matches any of the above-mentioned, this clears advertisements on the site from where this malware is hosted and displays ads, through a hidden iframe, from any of these sites:

  • http://www.{BLOCKED}eflash.cc/ads.html
  • http://www.{BLOCKED}eflash.cc/ads3{Random Number}.html
  • http://www.{BLOCKED}eflash.cc/c_rec.html
  • http://www.{BLOCKED}eflash.cc/c_sky.html

  SOLUTION

Minimum Scan Engine: 9.200

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/grayware files that dropped/downloaded JS_KOOBFACE.AC

    TROJ_KOOBFACE.AC

Step 3

Close all opened browser windows

Step 4

Scan your computer with your Trend Micro product to delete files detected as JS_KOOBFACE.AC. 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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