Analysis by: Homer Pacag

ALIASES:

W97M.Downloader (Symantec); TrojanDownloader:W97M/Adnel (Microsoft )

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan executes when a user accesses certain websites where it is hosted.

  TECHNICAL DETAILS

File Size: 126,976 bytes
File Type: DOC
Memory Resident: No
Payload: Downloads files

Arrival Details

This Trojan executes when a user accesses certain websites where it is hosted.

Download Routine

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

  • http://{BLOCKED}internet.net/js/bin.exe
  • http://{BLOCKED}arealestate.info/js/bin.exe

It saves the files it downloads using the following names:

  • %User Temp%\YEWMJFAHIB.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.)

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.354.05
FIRST VSAPI PATTERN DATE: 18 Dec 2014
VSAPI OPR PATTERN File: 11.355.00
VSAPI OPR PATTERN Date: 18 Dec 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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden folders in the search result.

Step 4

Scan your computer with your Trend Micro product to delete files detected as W97M_DLOADER.GHT. 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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