Disconnect your Mac from the internet
Quit suspicious apps and browser tabs
Restart your Mac in Safe Mode
Open Activity Monitor and force quit unfamiliar processes
Remove suspicious apps from the Applications folder
Delete suspicious login items in System Settings
Check and remove unknown browser extensions
Clear browser history, cache, and website data
Review and delete suspicious profiles in System Settings
Empty the Trash
Run a trusted malware scanner for Mac
Update macOS and all installed apps
Change important passwords from a clean device
Enable FileVault and built-in security features
Restore files from a known clean backup if needed