This code is a malicious PowerShell script that functions as...

This code is a malicious PowerShell script that functions as a keylogger. Here's what the script does step by step:

1. Imports User32 DLL Functions:

   • The script uses Add-Type to define and import API calls from the Windows user32.dll, such as:
     • GetAsyncKeyState: Captures key presses asynchronously for specified keys.
     • GetKeyboardState: Retrieves the state of all keys on the physical keyboard.
     • MapVirtualKey: Maps a virtual-key code to a scan code or character type.
     • ToUnicode: Converts keystroke data into Unicode characters, essentially interpreting the key pressed.

2. Alters Error Handling:

   • It suppresses error messages with $ErrorActionPreference = SilentlyContinue.

3. Creates a Scheduled Task:

   • A scheduled task named MomMonitor is created to run with administrator permissions, pointing to powershell.exe in hidden mode (-w h). This ensures persistence of the script across reboots.

4. Modifies the User Profile:

   • It writes the script's code to the user's PowerShell profile (profile.ps1), ensuring that the keylogger executes each time PowerShell is started.

5. Sets Up Logging:

   • It defines a log file in the system's temporary folder ($env:temp\mat-debug-6F936CD.log) to store captured keystrokes.

6. Initiates Keylogging:

   • In a while loop:
     • It continuously checks for keystrokes using GetAsyncKeyState.
     • Converts these keystrokes into human-readable characters using the imported APIs (MapVirtualKey and ToUnicode).
     • Appends the captured characters (in Unicode format) to the log file.

7. Data Exfiltration:

   • Every hour, the script sends the captured log data to a remote malicious server (http://{COMPUTERNAME}.malicious.12moms21.com) via Invoke-RestMethod. This effectively leaks the captured keystrokes (potential sensitive information) to the attacker.

8. Avoids Detection:

   • The script attempts to stay undetected by suppressing outputs and errors, scheduling itself to run stealthily, writing the log file in a temporary directory, and disguising key sections.

Summary:

This script is designed to:

• Monitor and log keystrokes typed by the user (keylogger functionality).
• Exfiltrate the logged data periodically to an attacker-controlled server.
• Establish persistence by creating a scheduled task and modifying the user's PowerShell profile.

Such a script is often used for unauthorized monitoring, data theft, or other malicious activities. It poses a significant security risk and should be identified and removed immediately.