W2KM_POWLOAD.HFF

May 30, 2018
 Analysis by: Hazel Ann Poligratis
 ALIASES:

Trojan:Win32/Bluteal!rfn (Microsoft), W97m.Downloader.GUP (BitDefender)

 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:

Downloaded from the Internet, Dropped by other malware, Spammed via email

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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

116,992 bytes

File Type:

DOC

Memory Resident:

No

Initial Samples Received Date:

28 May 2018

Payload:

Connects to URLs/IPs, Downloads files

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.

Download Routine

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

  • http://{BLOCKED}b.com/lhsm4tt/
  • http://{BLOCKED}odeideias.com.br/GgClcwx/
  • http://{BLOCKED}als.co.uk/elqlzK2/
  • http://{BLOCKED}i.com/IqN3J3Uea/
  • http://{BLOCKED}oder.me/tMwUlabc/

It saves the files it downloads using the following names:

  • %System Root%\Users\Public\{random filename}.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

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 does the following:

  • It uses Powershell commands to download and execute a malicious file:
    • PowersHeLL -WinDowsTyle hidden -e {encoded command}

NOTES:

The document contains the following message details luring users to enable macro content:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.280.05

FIRST VSAPI PATTERN DATE:

28 May 2018

VSAPI OPR PATTERN File:

14.281.00

VSAPI OPR PATTERN Date:

29 May 2018

Step 1

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 2

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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.
  • %System Root%\Users\Public\{random filename}.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 clean files detected as W2KM_POWLOAD.HFF. 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 the following Trend Micro Support pages for more information:


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