Analysis by: Leidryn Saludez
ALIASES:

Trojan:MSIL/FileCoder.ARA!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • 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.

It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 122,368 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 15 Feb 2024
Payload: Deletes files, Drops files, Encrypts 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:

  • C:\LockBIT\systemID → contains infected system ID

It adds the following processes:

  • "sc" config "SQL" start= demand
  • "sc" config "1C:" start= demand
  • "sc" config "IAS" start= demand
  • "sc" config "AnyDesk:" start= demand
  • "sc" config "VSS" start= demand
  • "sc" config "firebird" start= demand
  • "sc" config "Acronis" start= demand

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
taskhostw = {Malware Path}\{Malware Name}

Other System Modifications

This Ransomware deletes the following folders:

  • {Drive letter}:\$Recycle.Bin

Process Termination

This Ransomware terminates the following services if found on the affected system:

  • SQL
  • 1C:
  • IAS
  • AnyDesk
  • VSS
  • firebird
  • Acronis

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file path:

  • .exe
  • .msi
  • .zenhao007@gmail.com
  • .dll
  • C:\Windows
  • Readme
  • systemID

It appends the following extension to the file name of the encrypted files:

  • .{BLOCKED}baia@gmail.com.[affected system ID].{BLOCKED}007@gmail.com

It drops the following file(s) as ransom note:

  • {Encrypted Directory}\Readme.txt

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.160.02
FIRST VSAPI PATTERN DATE: 15 Feb 2024
VSAPI OPR PATTERN File: 19.161.00
VSAPI OPR PATTERN Date: 16 Feb 2024

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:

     WORM.Win32.TRX.XXPE50FFF077

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.
  • C:\LockBIT\systemID

Step 5

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.

  • {Drive letter}:\$Recycle.Bin

Step 6

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • taskhostw = {Malware Path}\{Malware Name}

Step 7

Restore encrypted files from backup.

Step 8

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.ZENFRI.THBAEBD. 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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