W2KM_DRIDEX.YSQU

 Analysis by: Rhena Inocencio

 ALIASES:

TrojanDownloader:O97M/Donoff (Microsoft), VBA/TrojanDownloader.Agent.AQH (ESET), W97M/Downloader.awf (McAfee)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • 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.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

DOC

Initial Samples Received Date:

28 Jan 2016

Arrival Details

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

Download Routine

This Trojan saves the files it downloads using the following names:

  • %User Temp%\zimbazi.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.)

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 connects to the following possibly malicious URL:

  • http://{BLOCKED}sr.com/nuyff45d/87tf23w.exe

However, as of this writing, the said sites are inaccessible.