Ransom.Win64.RANGGOL.A

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 executes then deletes itself afterward.

It encrypts files with specific file extensions. It drops files as ransom note.

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:

• %Application Data%\Windows_Update\Windows_Security.exe
• %User Temp%\Windows_Security.exe
• %Desktop%\Instructions.html ← ransom notes

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming 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).. %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).)

It adds the following processes:

• cmd /C \"mkdir %Application Data%\Windows_Update\"
• cmd /C \"timeout /t 5 & del {Original executable file} & start %Application Data%\Windows_Update\Windows_Security.exe"
• cmd /C \"timeout /t 5 & del {Original executable file} & start %User Temp%\Windows_Security.exe"
• cmd /C \"vssadmin.exe Delete Shadows /All /Quiet\"
• cmd /C REG ADD HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /V Windows-Defender /t REG_SZ /F /D %Application Data%\Windows_Update\Windows_Security.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming 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).)

It creates the following folders:

• %Application Data%\Windows_Update

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

It executes then deletes itself afterward.

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows-Defender = %Application Data%\Windows_Update\Windows_Security.exe

Other Details

This Ransomware does the following:

• After encrypting files it does the following:
  • It executes the following commands: cmd /C "%Desktop%\Instructions.html"
  • It displays the following:
    
• It connects to the following URL to check if the e-wallet is refilled to automatically decrypt all encrypted files:
  • http://btc.{BLOCKED}r.io/api/v1/address/info/1BwwT5zo5FwQdWniUSay2AUrPrbYph9SxP
• It won't continue to its malicious routine if one of the following condition is met:
  • If the following files are found on the following folders:
    • %System Root%\Python{version}\{files}
    • %System Root%\Python{version}\Scripts\{files}
    • %System Root%\Perl\bin\{files}
    • %System Root%\Perl\site\bin\{files}
    • Where files are the following:
      • cmd.com
      • cmd.exe
      • cmd.bat
      • cmd.cmd
      • cmd.vbs
      • cmd.vbe
      • cmd.js
      • cmd.jse
      • cmd.wsf
      • cmd.wsh
      • cmd.msc
      • cmd.py
      • cmd.pyw
  • If the following registries value return True:
    • HKEY_LOCAL_MACHINE\Software\Policis\done
    • HKEY_CURRENT_USER\Software\Policis\done

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• .asp
• .aspx
• .php
• .key
• .pps
• .pptx
• .mkv
• .mov
• .mpg
• .mpeg
• .avi
• .flv
• .wmv
• .swf
• .vob
• .class
• .cpp
• .java
• .rar
• .zip
• .tar.gz
• .ods
• .xlsx
• .odt
• .docx
• .pdf
• .wks
• .txt
• .jar
• .gif
• .bmp
• .jpg
• .jpeg
• .png
• .psd
• .svg
• .tif
• .tiff
• .mid
• .midi
• .mp3
• .wav
• .wma
• .txt
• .mdb
• .dbf
• .xml
• .sql
• .tar
• .bak

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

• tmp
• winnt
• Application Data
• AppData
• Program Files (x86)
• Program Files
• temp
• thumbs.db
• Recycle.Bin
• System Volume Information
• Boot
• Windows
• .enc
• Instructions
• Windows_Security.exe

It renames encrypted files using the following names:

• {Base64 encoded Filename and extension}.enc

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

• %Desktop%\Instructions.html