Analysis by: Cris Nowell Pantanilla
ALIASES:

Trojan-Downloader.MSWord.Agent.in (Kaspersky), TrojanDownloader:W97M/Adnel (Microsoft)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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: 57,856 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 13 Apr 2015

Arrival Details

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

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}ipcenaze.com/353/654.exe

It saves the files it downloads using the following names:

  • %User Temp%\rizob1.0.exe - detected as TSPY_DRIDEX.VVQX

(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.

Other Details

This is the Trend Micro detection for Microsoft Word documents that are compromised through the insertion of a malicious macro.

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.606.05
FIRST VSAPI PATTERN DATE: 13 Apr 2015
VSAPI OPR PATTERN File: 11.607.00
VSAPI OPR PATTERN Date: 14 Apr 2015

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 the malware/grayware file dropped/downloaded by W2KM_DLOAD.XMNH. (Note: Please skip this step if the threat(s) listed below have already been removed.)

     TSPY_DRIDEX.VVQX

Step 3

Scan your computer with your Trend Micro product to delete files detected as W2KM_DLOAD.XMNH. 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.

Step 4

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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