TROJ_UPATRE.YYKE

April 02, 2014
 Analysis by: Adrian Cofreros
 ALIASES:

TrojanDownloader:Win32/Upatre.A(Microsoft),Win32/TrojanDownloader.Waski.B trojan(NOD32),Trojan.Win32.Bublik.cehk(Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email

This malware is related to the new spam technique wherein a mail has an.MSG attachment. The said .MSG attachment, in actual contains this UPATRE variant.

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 itself after execution.

  TECHNICAL DETAILS

File Size:

18,432 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

01 Apr 2014

Payload:

Downloads files

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%\budha.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 accesses the following websites to download files:

  • http://{BLOCKED}dults.com/images/2703USd.git
  • http://{BLOCKED}ark.com/Templates/2703USd.git

It saves the files it downloads using the following names:

  • %User Temp%\kilf1.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.)

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.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.700.02

FIRST VSAPI PATTERN DATE:

01 Apr 2014

VSAPI OPR PATTERN File:

10.701.00

VSAPI OPR PATTERN Date:

01 Apr 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %User Temp%\kilf1.exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_UPATRE.YYKE. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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