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JS_BLOCKER.J
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Encrypted: No
In the wild: Yes

Overview


Infection Channel: Downloaded from the Internet

This malware downloads a malicious script detected as HTML_BLOCKER.K, which is used to send the Facebook messages with the link to the video.

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

This Trojan may be downloaded from remote sites by other malware.

Technical Details


File size: 2,593 bytes
File type: JS
Initial samples received date: 22 Jan 2014
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

This Trojan may be downloaded from the following remote site(s):

  • http://{BLOCKED}f.biz/ajax/background.js

It may be downloaded from remote site(s) by the following malware:

  • TROJ_BLOCKER.J

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://www.{BLOCKED}p.us/user.php - detected as HTML_BLOCKER.K

It connects to the following URL(s) to download its configuration file:

  • http://www.{BLOCKED}s.net/ajax/get.js?amtasak={value}

Information Theft

This Trojan s configuration file contains the following information:

  • List of URLs to be blocked

NOTES:

It prevents Chrome from accessing the following URLs:

  • virustotal.com
  • avast.com
  • eset.com
  • microsoft.com
  • virusscan.jotti.org
  • jotti.org
  • avg.com
  • kaspersky.com.tr
  • kaspersky.com
  • facebook.com/ajax/webstorage/process_keys.php
  • facebook.com/checkpoint/malware/cr_ext_config
  • facebook.com/checkpoint/malware/cr_ext_log
  • sansurcrx.com
  • dl.dropboxusercontent.com
  • sosyalmedyakusu.com
  • fiddle.jshell.net
  • fei-coder.com
  • docs.google.com
  • drive.google.com
  • orjinalmarket.net
  • facebook.com/ajax/follow/unfollow_profile.php
  • vuupc.com
  • mcafee.com
  • s3.amazonaws.com
  • googlecode.com

It also prevents Chrome from accessing the Extensions page by closing tabs with the following strings:

  • chrome://chrome/extensions
  • opera://extensions
  • chrome://extensions/

Solution


Minimum scan engine: 9.700
First VSAPI Pattern File: 10.556.06
First VSAPI Pattern Release Date: 23 Jan 2014
VSAPI OPR Pattern Version: 10.557.00
VSAPI OPR Pattern Release Date: 23 Jan 2014

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 JS_BLOCKER.J

    • TROJ_BLOCKER.J

Step 3

Remove malware/grayware files dropped/downloaded by JS_BLOCKER.J

    • HTML_BLOCKER.K

Step 4

Close all opened browser windows

Step 5

Scan your computer with your Trend Micro product to delete files detected as JS_BLOCKER.J. 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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Analysis By: Anthony Joe Melgarejo

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