TROJ_UPATRE.YQU

It is a malicious attachment related to a tax-themed spam campaign. The malware connects to malicious URLs to download an encrypted version of a ZBOT variant, which disables the antivirus products installed in the system.

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.

It deletes the initially executed copy of itself.

Arrival Details

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

Installation

This Trojan drops the following copies of itself into the affected system and executes them:

• %User Temp%\lsame.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.)

Download Routine

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

• http://vtiger.{BLOCKED}inc.com/test/logo/0804UKr.jpi - detected as TROJ_UPATRE.CFG
• http://{BLOCKED}inc.com/wp-content/uploads/2014/04/0804Ukr.jpi - inaccessible

It saves the files it downloads using the following names:

• %User Temp%\tislu.exe - detected as TSPY_ZBOT.YQU

(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 deletes the initially executed copy of itself