Analysis by: Sammy Chua
ALIASES:

Trojan-Downloader.MSExcel.Agent.am (Kaspersky); TrojanDownloader:W97M/Dowtre.A (Microsoft); 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

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. 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 attempts to access certain websites. However, the websites are inaccessible as of this writing.

  TECHNICAL DETAILS

File Size: 68,096 bytes
File Type: XLS
Memory Resident: No
Initial Samples Received Date: 16 Jul 2015

Arrival Details

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

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

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\{random number}.bat
  • %User Temp%\{random number}.vbs
  • %User Temp%\{random number}.ps1 - for Windows Vista and above only
  • %User Temp%\8.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.)

Other Details

This Trojan attempts to access certain websites. However, the websites are inaccessible as of this writing.

It connects to the following possibly malicious URL:

  • http://{BLOCKED}althyenergydrinks.com/wp-content/themes/twentytwelve/78672738612836.txt
  • http://www.{BLOCKED}ndetail.com/wp-content/uploads/78672738612836.txt
  • http://{BLOCKED}althyenergydrinks.com/wp-content/themes/twentytwelve/papa.txt
  • http://www.{BLOCKED}ndetail.com/wp-content/uploads/papa.txt
  • http://{BLOCKED}y.com/wp-content/plugins/reading-time/pa.exe
  • http://{BLOCKED}c.su/5751812.jpg
  • http://{BLOCKED}c.su/5757956.jpg

  SOLUTION

Minimum Scan Engine: 9.750

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 this file

[ 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%\{random number}.bat
  • %User Temp%\{random number}.vbs
  • %User Temp%\{random number}.ps1
  • %User Temp%\8.exe

Step 4

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]

Step 5

Scan your computer with your Trend Micro product to delete files detected as X2KM_NAMAGIF.WQ. 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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