Analysis by: Cris Nowell Pantanilla
 THREAT SUBTYPE:

Malicious Downloader

 PLATFORM:

Windows

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

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 32,768 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Jun 2015
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

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

This malware arrives via the following means:

  • Attachment to spammed malicious emails by remote malicious user or other malware.
  • Attachment to spammed malicious emails as a password-protected archive.
  • Downloaded from a link embedded in spammed emails.

Installation

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

  • %User Temp%\{random}.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 deletes the initially executed copy of itself

NOTES:

This malware accesses a remote site where it downloads other malicious files into the system. It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It saves the downloaded files using random names in the %User Temp% folder.

This malware may download files related to the following malware family, among others:

  • TSPY_ZBOT
  • TSPY_DYRE
  • BKDR_VAWTRAK
  • TROJ_CRYPWALL

  SOLUTION

Minimum Scan Engine: 9.700

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

Identify and terminate files detected as TROJ_UPATRE

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_UPATRE. 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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