Analysis by: Leidryn Saludez
ALIASES:

PwrSh:Agent-AV [Ransom] (AVAST)

 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 encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size: 10,033 bytes
File Type: PS1
Memory Resident: No
Initial Samples Received Date: 21 Mar 2024
Payload: Displays graphics/image, Encrypts files, Drops files, Connects to URLs/IPs, Collects system information, 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 adds the following processes:

  • "%System%\NOTEPAD.EXE" %Desktop%\README.txt

(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).)

Other System Modifications

This Ransomware changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\control panel\desktop
wallpaper = %Temp%\photo.jpg

Information Theft

This Ransomware gathers the following data:

  • satellite:IP
    • IP address
  • bust_in_silhouette: User Information
    • Language
    • Current date and time
    • User Name
    • Computer Name
  • shield: Antivirus
    • Installed antivirus software
  • computer: Hardware
    • Display resolution
    • OS version
    • OS build
    • Manufacturer
    • Model
    • CPU name
    • GPU name
    • RAM
    • UUID
    • MAC address
    • Uptime
  • floppy_disk: Disk
    • All disk information

Other Details

This Ransomware encrypts files with the following extensions:

  • .7z
  • .docx
  • .gif
  • .gz
  • .ini
  • .jpg
  • .pdf
  • .psd
  • .png
  • .rtf
  • .txt
  • .zip
  • .accd
  • .avi
  • .csv
  • .doc
  • .jpeg
  • .midi
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpeg2
  • .mpeg3
  • .mpg
  • .ogg
  • .ppt
  • .xls

It does the following:

  • It deletes all shadow copies on the system.
  • It attempts to download from this URL to use as wallpaper
    • https://{BLOCKED}fshore.cat/HrD5nI4Z.cat → %Temp%\photo.jpg

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %Downloads%

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

  • .biden

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

  • %Desktop%\README.txt

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.246.03
FIRST VSAPI PATTERN DATE: 29 Mar 2024
VSAPI OPR PATTERN File: 19.247.00
VSAPI OPR PATTERN Date: 30 Mar 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

Reset your Desktop properties

[ Learn More ]

Step 3

Restore encrypted files from backup.

Step 4

Scan your computer with your Trend Micro product to delete files detected as Ransom.PS1.NEDIB.THCBIBD. 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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