TROJ_UPATRE.YYRK

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

It deletes itself after execution.

Arrival Details

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

• %User Temp%\uaygf.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other System Modifications

This Trojan adds the following registry keys:

HKLM\Software\Microsoft\
ESENT\Process\document81723\
DEBUG
Trace Level = null

Download Routine

This Trojan accesses the following websites to download files:

• http://{BLOCKED}ersalliance.org/wp-includes/images/guid11.pdf
• http://{BLOCKED}ksupport.net/docs/guid11.pdf

It saves the files it downloads using the following names:

• %Windows%\bOgFvXkJnpTpwX.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

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 itself after execution.

NOTES:

This Trojan accesses the URL {BLOCKED}.{BLOCKED}.35.133:33136/0912us21/{Computer Name}/0/{OS Version}-{Service Pack}/0/ to send information. The following information are posted:

• Computer name
• Operating system version
• Service pack installed