JS_SHESDE.E

This malware exploits the (MS13-022) Vulnerability in Silverlight Could Allow Remote Code Execution (2814124) vulnerability to run malicious code on a system through a specially-crafted app.

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

This Trojan executes when a user accesses certain websites where it is hosted.

As of this writing, the said sites are inaccessible.

Arrival Details

This Trojan executes when a user accesses certain websites where it is hosted.

It may be downloaded from the following remote sites:

• http://{BLOCKED}nriomafra.com.br/viewer/4/201402/244401107.htm

Installation

This Trojan drops the following file(s)/component(s):

• %User Temp%\papa.vbs - VBS_SHESDE.D

(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.)

Download Routine

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

• http://{BLOCKED}nriomafra.com.br/5995.mp3

It saves the files it downloads using the following names:

• %User Temp%\{Random Filename}.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.)

As of this writing, the said sites are inaccessible.

NOTES:

This Trojan contains an embedded object that loads the following malicious Microsoft® Silverlight® application.

• http://{BLOCKED}nriomafra.com.br/it/ca/pl/555728458.xap

This Trojan drops its component if using the following browser agent.

• MSIE Trident version 4, 5 and 6.