TROJ_UPATRE.YYSHH

 Analysis by: Pearl Charlaine Espejo

 ALIASES:

Trojan-Downloader.Win32.Upatre.fek (Kaspersky); TR/Upatre.5617751 (Avira); Win32/TrojanDownloader.Waski.F (ESET-NOD32); Upatre-FAAR!436DA4D7AEE7 (McAfee); Trojan.Email.FakeDoc (Malwarebytes)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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 deletes itself after execution.

  TECHNICAL DETAILS

File Size:

37,632 bytes

File Type:

, EXE

Initial Samples Received Date:

25 Feb 2015

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%\bestviewer.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.)

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\best62D4.txt
  • %User Temp%\viagra.pdf
  • %User Temp%\{random filename}.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 Details

This Trojan connects to the following possibly malicious URL:

  • {BLOCKED}ternational.com/mandoc/facth.pdf
  • {BLOCKED}nc.co.uk/lee/facth.pdf
  • {BLOCKED}.{BLOCKED}.152.131:14141/2502us22/

It deletes itself after execution.