Analysis by: Francesca Villasanta
ALIASES:

VHO:Trojan.Win32.Convagent.gen (KASPERSKY)

 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.

It drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size: 1,335,183 bytes
Memory Resident: No
Initial Samples Received Date: 14 Sep 2023
Payload: 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 adds the following processes:

  • powershell.exe vssadmin Delete Shadows /All /Quiet
  • powershell.exe wbadmin DELETE BACKUP -keepVersions:0 -quiet

Other Details

This Ransomware does the following:

  • It will only execute if system date is from 01/Jun/2022 to 16/Sept/2023.
  • It is capable of encrypting network shares.

Ransomware Routine

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

  • File recovery-your ID_{Hard-coded ID from configuration}.txt

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

  • C:\Windows
  • C:\ProgramData
  • C:\Program Files (x86)
  • C:\Program Files
  • C:\msys64

It renames encrypted files using the following names:

  • {8 random}{Hex encoded original extension}{3 digits representing the count of the Hex-encoded extension in decimal}.live

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

  • {8 random}{Hex encoded original extension}{3 digits representing the count of the Hex-encoded extension in decimal}.live

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

  • {Encrypted Drive\Directory}\File recovery-your ID_{Hard-coded ID from configuration}.txt

It avoids encrypting files with the following file extensions:

  • .themepack
  • .bin
  • .scr
  • .ico
  • .ini
  • .shs
  • .dll
  • .icl
  • .url
  • .ps1
  • .wpx
  • .live
  • .spl
  • .sys
  • .msp
  • .rom
  • .bat
  • .tmp
  • .exe
  • .nls
  • .msc
  • .lnk

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.144.01
FIRST VSAPI PATTERN DATE: 06 Feb 2024
VSAPI OPR PATTERN File: 19.145.00
VSAPI OPR PATTERN Date: 07 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:

     TROJ.Win32.TRX.XXPE50FFF076

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 files detected as Ransom.Win64.LIVEDE.A

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {Encrypted Directory}\File recovery-your ID_{Hard-coded ID from configuration}.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.LIVEDE.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 6

Restore encrypted files from backup.


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