Analysis by: Melvin Jhun Palbusa
 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • 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: 5,359,104 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 12 Jan 2024
Payload: Collects system information, Drops files, Encrypts files, Steals information

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:

  • %Desktop%\encrypted_master_key.txt
  • %User Temp%\enc{random number}

(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Information Theft

This Ransomware gathers the following data:

  • Hostname
  • Architecture
  • BootTime
  • KernelVersion
  • IP address
  • MAC Address
  • OS
  • Time Zone
  • UID

Other Details

This Ransomware encrypts files with the following extensions:

  • .3ds
  • .7z
  • .accdb
  • .ai
  • .asp
  • .aspx
  • .avhd
  • .avi
  • .back
  • .bak
  • .c
  • .cfg
  • .conf
  • .cpp
  • .cs
  • .ctl
  • .dbf
  • .disk
  • .djvu
  • .doc
  • .docx
  • .dwg
  • .eml
  • .fdb
  • .giff
  • .go
  • .gz
  • .h
  • .hdd
  • .jar
  • .jpeg
  • .jpg
  • .kdbx
  • .mail
  • .mdb
  • .mpeg
  • .mpg
  • .msg
  • .nrg
  • .ora
  • .ost
  • .ova
  • .ovf
  • .pdf
  • .php
  • .pmf
  • .png
  • .ppt
  • .pptx
  • .pst
  • .pvi
  • .py
  • .rtf
  • .sln
  • .sql
  • .tar
  • .tiff
  • .vcb
  • .cfd
  • .vmc
  • .vms
  • .vsv
  • .work
  • .xls
  • .xlsx
  • .xvd
  • .zip

It does the following:

  • Does not encrypt file if it lacks the required access permission

Ransomware Routine

This Ransomware appends the following extension to the file name of the encrypted files:

  • .{33 Random Alphanumeric Character}.abcd

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

  • %Desktop%\encrypted_master_key.txt

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.104.05
FIRST VSAPI PATTERN DATE: 18 Jan 2024
VSAPI OPR PATTERN File: 19.105.00
VSAPI OPR PATTERN Date: 19 Jan 2024

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

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.  
  • %Desktop%\encrypted_master_key.txt
  • %User Temp%\enc{random number}

Step 4

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.BOCKLIT.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 5

Restore encrypted files from backup.


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