Analysis by: Jayvee Mark Villaroman
 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 2,078,720 bytes
File Type: EXE
File Compression: UPX
Memory Resident: Yes
Initial Samples Received Date: 29 Mar 2023
Payload: Connects to URLs/IPs, Drops files, Modifies system registry

Arrival Details

This Ransomware 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 Ransomware drops the following files:

  • %Windows%\Help\list.log

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

It adds the following processes:

  • bcdedit /set {current} safeboot minimal <- boots Windows into safe mode
  • shutdown -f -r -t 0 <- forced shutdown and restart

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\eventlog\Application\
MSlogon
CustomSource = 1

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\eventlog\Application\
MSlogon
EventMessageFile = %SystemRoot%\System32\EventCreate.exe

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\eventlog\Application\
MSlogon
TypesSupported = 7

Download Routine

This Ransomware connects to the following URL(s) to download its component file(s):

  • http://cgh8mfervgto8tr8q9egpdwrqii45tmjb.{BLOCKED}t.me/hh.aspx?h={random incrementing number)

Other Details

This Ransomware adds and runs the following services:

MSlogon
MSlogon = {Malware file path}\{Malware file name}.exe

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.378.02
FIRST VSAPI PATTERN DATE: 12 Apr 2023
VSAPI OPR PATTERN File: 18.379.00
VSAPI OPR PATTERN Date: 13 Apr 2023

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:

    Troj.Win32.TRX.XXPE50FFF067

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

Disable this malware service

[ Learn More ]
  • MSlogon

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\eventlog
    • Application = MSlogon

Step 6

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. %Windows%\Help\list.log

Step 7

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.IRONLOCKER.A.go. 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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