Analysis by: Bren Matthew Ebriega
ALIASES:

TrojanDownloader:O97M/Obfuse.JM!MTB (MICROSOFT); Trojan-Downloader.VBA.Agent (IKARUS)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 147,195 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 22 Oct 2020
Payload: Downloads files, Connects to URLs/IPs

Arrival Details

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

Installation

This Trojan adds the following processes:

  • If download is successful:
    • %System%\regsvr32.exe %All Users Profile%\EZvtA.txt

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

Download Routine

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

  • http://{BLOCKED}8.com/biwe_zibofyra/ripy_lani.php?l=qedux14.cab

It saves the files it downloads using the following names:

  • %All Users Profile%\EZvtA.txt

(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.302.04
FIRST VSAPI PATTERN DATE: 22 Oct 2020
VSAPI OPR PATTERN File: 16.303.00
VSAPI OPR PATTERN Date: 23 Oct 2020

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Downloader.VBA.TRX.XXVBAF01FF010

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

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.
  • %All Users Profile%\EZvtA.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.W97M.SHATHAK.A. 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:

Step 6

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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