Analysis by: Rhena Inocencio
ALIASES:

Trojan:JS/Medfos.B (Microsoft)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

This is the Trend Micro detection for files that contain a malicious script. It redirects browsers to certain sites.

  TECHNICAL DETAILS

File Size: Varies
File Type: JS
Memory Resident: No
Initial Samples Received Date: 04 Feb 2013

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Other Details

This is the Trend Micro detection for files that contain a malicious script.

It redirects browsers to the following sites:

  • http://{BLOCKED}omeweb.com/feed?type=search&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.164.184.36&ref=&uu={random values}
  • http://{BLOCKED}e-instant-search.com/js/disable.js?type=live&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.256.215.67&ref=&gsu={random values}
  • http://{BLOCKED}e-instant-search.com/js/disable.js?type=live&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.146.65.222&ref=&gsu={random values}
  • http://{BLOCKED}e-instant-search.com/js/disable.js?type=live&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.89.203.213&ref=&gsu={random values}
  • http://{BLOCKED}e-instant-search.com/js/disable.js?type=live&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.65.71.64&ref=&gsu={random values}
  • http://{BLOCKED}e-instant-search.com/js/disable.js?type=live&user-agent=Mozilla%2F5.0+%28Windows+NT+5.1%29+AppleWebKit%2F534.30+%28KHTML%2C+like+Gecko%29+Chrome%2F12.0.742.112+Safari%2F534.30&ip=84.0.151.82&ref=&gsu={random values}

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.706.05
FIRST VSAPI PATTERN DATE: 04 Feb 2013
VSAPI OPR PATTERN File: 9.707.00
VSAPI OPR PATTERN Date: 05 Feb 2013

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

Close all opened browser windows

Step 3

Scan your computer with your Trend Micro product to delete files detected as JS_MEDFOS.SM. 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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