Ransom.Win64.PIRCEN.THHOEBD.go

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.

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:

• %User Temp%\Wallpaper.png

(Note: %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).)

It adds the following processes:

• powershell -Command "(New-Object System.Net.WebClient).DownloadFile('https://i.imgur.com/RfsCOES.png', '%User Temp%\Wallpaper.png')"
• powershell -Command "Add-Type -TypeDefinition 'using System; using System.Runtime.InteropServices; public class Wallpaper { [DllImport(\"user32.dll\", CharSet = CharSet.Auto)] public static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni); public static void Set(string path) { SystemParametersInfo(20, 0, path, 3); } }'; [Wallpaper]::Set('%User Temp%\Wallpaper.png')"

Other System Modifications

This Ransomware sets the system's desktop wallpaper to the following image:

• %User Temp%\Wallpaper.png
  

Download Routine

This Ransomware accesses the following websites to download files:

• https://{BLOCKED}r.com/RfsCOES.png

Ransomware Routine

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

• bootmgr
• bcd
• desktop.ini
• config.sys
• autoexec.bat
• decryption instructions.txt

It avoids encrypting files found in the following folders:

• windows
• system32
• programdata
• program files
• program files (x86)
• public
• system volume information
• \system volume information
• efi
• boot
• public
• perflogs
• microsoft
• intel
• appdata
• .dotnet
• .gradle
• .nuget
• .vscode
• msys64

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

• {Encrypted Directory}\decryption instructions.txt
  

It avoids encrypting files with the following file extensions:

• .sys
• .exe
• .dll
• .com
• .scr
• .bat
• .vbs
• .ps1
• .lnk
• .inf
• .reg
• .msi
• .ini