Analysis by: Raymart Christian Yambot
 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.

  TECHNICAL DETAILS

File Size: 15,872 bytes
File Type: , EXE
Memory Resident: No
Initial Samples Received Date: 17 Apr 2023
Payload: Drops files, Displays graphics/image, Encrypts files

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:

  • %AppDataLocal%\iv.bin → Initialization Vector used for encryption
  • %AppDataLocal%\key.bin → Key used for encryption

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Ransomware does the following:

  • Encrypts all files within the desktop folder.
  • Features three buttons with the following actions:
    • Shutdown
      • Initiate system shutdown.
    • Destroy System
      • Triggers the system to enter blue sreen state(Blue Screen of Death).
    • Destroy Key
      • Delete the following files used for encryption:
        • %AppDataLocal%\iv.bin
        • %AppDataLocal%\key.bin
  • It displays the following GUI as its ransom note:

Ransomware Routine

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

  • {Original File name}.{Original Extension}.RBX

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.390.05
FIRST VSAPI PATTERN DATE: 17 Apr 2023
VSAPI OPR PATTERN File: 18.391.00
VSAPI OPR PATTERN Date: 18 Apr 2023

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.
  • %AppDataLocal%\iv.bin
  • %AppDataLocal%\key.bin

Step 4

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.RANBLOX.THDAGBC. 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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