TROJ_FEBUSER.A

July 28, 2013
 Analysis by: Anthony Joe Melgarejo
 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: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Via social networking sites

This malware is related to the malicious link spammed via Facebook that allegedly points to a video recording of a young woman committing suicide on camera. When executed it drops malicious files and installs bogus browser plugins detected as JS_FEBUSER.A.

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

This Trojan may arrive on a system by clicking spammed malicious links on the social networking site Facebook.

  TECHNICAL DETAILS

File Size:

229,776 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

25 Jul 2013

Payload:

Drops files

Arrival Details

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

  • http://s3-sa-east-1.{BLOCKED}aws.com/iframesu/ch.html

It may arrive on a system by clicking spammed malicious links on the social networking site Facebook.

Installation

This Trojan drops the following component file(s):

  • %User Temp%\1.crx - detected as JS_FEBUSER.A
  • %User Temo%\2.xpi - detected as JS_FEBUSER.A
  • %User Temp%\fbinstupd.exe - also detected as TROJ_FEBUSER.A
  • %User Temp%\lkaseoihcaig.exe - also detected as TROJ_FEBUSER.A

(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 drops the following non-malicious file:

  • %User Temp%\sqlite3.dll

(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.)

NOTES:

This malware installs the following extensions as Mozilla Service Pack 5.0 (for Mozilla Firefox)/Chrome Service Pack (for Google Chrome) to certain web browsers:

  • .crx (for Google Chrome)
  • .xpi (for Mozilla Firefox)

It connects to the following URL to update its stat counter:

  • http://whos.{BLOCKED}g.us/widget/okinstallchi.pnh

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

10.176.07

FIRST VSAPI PATTERN DATE:

25 Jul 2013

VSAPI OPR PATTERN File:

10.177.00

VSAPI OPR PATTERN Date:

25 Jul 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

Remove malware/grayware files dropped/downloaded by TROJ_FEBUSER.A

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_FEBUSER.A. 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.

NOTES:
To uninstall add-ons or plug-ins to your web browser, please follow these steps:

For Chrome users:

  • Refer to this page for uninstall extension instructions.
  • Select the Chrome Service Pack as the add-on or extension to remove or uninstall.
For Firefox users:
  • Refer to this page for add-on removal instructions.
  • Select the Mozilla Service Pack 5.0 as the add-on or extension to remove or uninstall.


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