JS_SHELL.GNM

 Analysis by: Jimelle Monteser

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This Trojan may be dropped by other malware.

It executes then deletes itself afterward.

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

  TECHNICAL DETAILS

File Size:

2,822 bytes

File Type:

JS

Memory Resident:

No

Initial Samples Received Date:

22 Aug 2013

Arrival Details

This Trojan may be dropped by other malware.

Installation

This Trojan executes then deletes itself afterward.

Download Routine

This Trojan saves the files it downloads using the following names:

  • %User Temp%\820.rtf
  • %User Temp%\iexplore.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

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 connects to the following possibly malicious URL:

  • http://{BLOCKED}le2.{BLOCKED}arecenter.com/virtual/news/820.rtf
  • http://{BLOCKED}le2.{BLOCKED}arecenter.com/virtual/news/s.exe

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.234.02

FIRST VSAPI PATTERN DATE:

23 Aug 2013

VSAPI OPR PATTERN File:

10.235.00

VSAPI OPR PATTERN Date:

24 Aug 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

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\820.rtf
  • %User Temp%\iexplore.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as JS_SHELL.GNM. 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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