Trojan.Win64.LOCMENT.YMAF-A

 Analysis by: Bren Matthew Ebriega

 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:

Dropped by other malware, Downloaded from the Internet


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.

  TECHNICAL DETAILS

File Size:

17,920 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Jun 2020

Payload:

Deletes files

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:

  • %System%\cmd.exe /C bcedit.exe /deletevalue {current} safeboot
  • %System%\cmd.exe /C sc config locloc start= disabled
  • {Malware Directory}\{Malware Filename}.exe runner → Detected as Ransom.Win32.LOCMENT.YMAF-A

Other System Modifications

This Trojan deletes the following files:

  • %Program Files%\Trend Micro\Deep Security Agent\Notifier.exe
  • %Program Files%\Trend Micro\Deep Security Agent\ds_monitor.exe
  • %Program Files%\Trend Micro\Deep Security Agent\dsa.exe
  • %Program Files%\Trend Micro\AMSP\coreFrameworkHost.exe
  • %Program Files%\Trend Micro\AMSP\coreServiceShell.exe
  • %Program Files%\Malwarebytes Endpoint Agent\UserAgent\Endpoint Agent Tray.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.924.01

FIRST VSAPI PATTERN DATE:

10 Jun 2020

VSAPI OPR PATTERN File:

15.925.00

VSAPI OPR PATTERN Date:

11 Jun 2020

Step 1

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 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

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.  

  • %Program Files%\Trend Micro\Deep Security Agent\Notifier.exe
  • %Program Files%\Trend Micro\Deep Security Agent\ds_monitor.exe
  • %Program Files%\Trend Micro\Deep Security Agent\dsa.exe
  • %Program Files%\Trend Micro\AMSP\coreFrameworkHost.exe
  • %Program Files%\Trend Micro\AMSP\coreServiceShell.exe
  • %Program Files%\Malwarebytes Endpoint Agent\UserAgent\Endpoint Agent Tray.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win64.LOCMENT.YMAF-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:


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