Disconnect from the internet
Disconnect external drives and USB devices
Restart the computer in Safe Mode
Run a full scan with your antivirus software
Update your antivirus definitions
Run a second scan with a trusted anti-malware tool
Quarantine or delete detected threats
Uninstall suspicious programs
Remove unknown browser extensions
Clear temporary files and browser cache
Check startup programs and disable suspicious entries
Update your operating system and software
Change passwords from a clean device
Restore files from a clean backup if needed
If the virus remains, back up important files and reinstall the operating system