Threat Encyclopedia

TROJ_WMSHELL.A

Publish date: November 05, 2014

ALIASES:

VBA/TrojanDownloader.Agent.BU (ESET), Virus:X97M/Domaw.A (Microsoft)

PLATFORM:

Windows

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

  • Threat Type:Trojan

  • Destructiveness:No

  • Encrypted: No

  • In the wild: Yes

OVERVIEW

Infection Channel:

Spammed via email


This malware is involved in the DRIDEX malspam campaign that was spotted in early November 2014. It purports itself as a word document with malicious macro code that then downloads DRIDEX onto the affected system. Users affected by this malware may find their online banking accounts compromised.

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.

TECHNICAL DETAILS

File Size:

137,728 bytes

File Type:

DOC

Initial Samples Received Date:

28 Oct 2014

Payload:

Downloads files

Arrival Details

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

Download Routine

This Trojan accesses the following websites to download files:

  • http://{BLOCKED}ehurt.com.pl/js/bin.exe

It saves the files it downloads using the following names:

  • %User Temp%\calc1.exe - detected as TSPY_DRIDEX.WQJ

(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.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.240.07

FIRST VSAPI PATTERN DATE:

28 Oct 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

Remove malware/grayware files dropped/downloaded by TROJ_WMSHELL.A. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • TSPY_DRIDEX.WQJ

Step 3

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


Did this description help? Tell us how we did.

Featured Stories

Connect with us on