W2KM_BARTALEX.SMA

BARTALEX is a macro malware responsible to a spam outbreak affecting enterprises. It uses Microsoft document and social engineering lures, which in this case, it leverages Automated Clearing House.

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

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops and executes the following files:

• %User Temp%\{random numbers}.vbs
• %User Temp%\{random numbers}.bat
• %User Temp%\{random numbers}.ps1 (For OS Version Vista and above)

(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, 7, and 8.)

Download Routine

This Trojan accesses the following websites to download files:

• http://{BLOCKED}rteyn.be/wp-content/themes/twentytwelve/1623782.txt
• http://{BLOCKED}SAM.COM/TMP/1623782.TXT
• https://www.{BLOCKED}x.com/s/qdbl9s2gpmf50dt/rr_1.exe?dl=1
• http://{BLOCKED}c.su/5577987.png

It saves the files it downloads using the following names:

• %User Temp%\8.exe - detected as TSPY_DYRE.YUYCC
• %User Temp%\444.jpg

(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, 7, and 8.)

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