Analysis by: Homer Pacag

ALIASES:

TrojanDownloader:W97M/Adnel (Microsoft); VBA/TrojanDownloader.Agent.IM (ESET-NOD32); Trojan.MSExcel.Agent.g (Kaspersky); W97M.Downloader (Symantec);

 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, Dropped by other malware, Downloaded from the Internet

This Trojan arrives as attachment to mass-mailed email messages. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes downloaded files whose malicious routines are exhibited by the affected system.

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

  TECHNICAL DETAILS

File Size: 112,128 bytes
File Type: XLS
Initial Samples Received Date: 20 Feb 2015
Payload: Downloads files

Arrival Details

This Trojan arrives as attachment to mass-mailed email messages.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Download Routine

This Trojan downloads the file from the following URL and renames the file when stored in the affected system:

  • http://{BLOCKED}3.{BLOCKED}1.28.235/kwefewef/fgdsee/dxzq.jpg

It saves the files it downloads using the following names:

  • %User Temp%\JIOiodfhioIH.cab then rename into %User Temp%\JIOiodfhioIH..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 executes downloaded files :

  • %User Temp%\JIOiodfhioIH..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.)

whose malicious routines are exhibited by the affected system.

Other Details

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

  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

Search and delete these files

[ 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%\JIOiodfhioIH..exe

Step 3

Scan your computer with your Trend Micro product to delete files detected as X2KM_DLOADR.E. 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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