Analysis by: Alvin John Nieto

 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: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This malware uses the exploit targeting (MS13-022) Vulnerability in Silverlight Could Allow Remote Code Execution (2814124) vulnerability. The said exploit was found to be the payload of a series of redirections that started from a website on how to avoid income tax in Canada.

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

This Trojan may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size: 22,016 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 23 Feb 2014
Payload: Downloads files

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

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

Installation

This Trojan drops the following component file(s):

  • %User Temp%\papa.vbs - contains download, decryption, and execution routines

(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 executes then deletes itself afterward.

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://{URL domain}/{random characters}.mp3 - acquired from the "url" parameter

It saves the files it downloads using the following names:

  • %User Temp%\{4 random characters}.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.)

Other Details

This Trojan is a zero-day exploit for the following vulnerability:

NOTES:

This Trojan requires the following parameters supplied by a component to perform its intended routine:

  • url - contains the URL where it connects to download the file it decrypts and executes

  SOLUTION

Minimum Scan Engine: 9.700
VSAPI OPR PATTERN File: 10.625.00
VSAPI OPR PATTERN Date: 24 Feb 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

Close all opened browser windows

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_SHESDE.E. 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.

Step 4

Download and apply this security patch Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


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