Trojan.BAT.CRYNOX.RGN

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It does not have any propagation routine.

It does not have any backdoor routine.

As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

Arrival Details

This Trojan 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 Trojan drops the following files:

• {Malware File Path}\temp.vbs → Creates a shortcut file in %Desktop% of all the files the malware has renamed. Deleted afterwards.
• %Desktop%\{File Name Of Renamed File}.lnk

(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).)

It adds the following processes:

• powershell -Command "$hwnd = (Get-Process -Id $PID).MainWindowHandle; ^
• reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System" /v DisableTaskMgr /t REG_DWORD /d 1 /f
• powershell -Command "Invoke-WebRequest 'https://{BLOCKED}awn.vercel.app/ReatCryptSC.ico' -OutFile %User Temp\ReatCryptSC.ico'"
• cscript //nologo temp.vbs

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

• https://{BLOCKED}awn.vercel.app/ReatCryptSC.ico

It saves the files it downloads using the following names:

• %User Temp%\ReatCryptSC.ico → Set as the icon of shortcut files created in %Desktop%.

(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).)

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan does the following:

• It uses PowerShell to disable the close button of the Command Prompt window.
• It disables the Task Manager.
• It deletes files found in %Desktop% with the following file extension:
  • .lnk
• It checks the %System%\User folder recursively for files with the following extensions:
  • .dll
  • .docx
  • .exe
  • .jpg
  • .m4a
  • .mp3
  • .pdf
  • .png
  • .pptx
  • .txt
• It appends the following file extension to the said file if found:
  • .CRYNOX

(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).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It does not exploit any vulnerability.