Malwarebytes Chameleon can be used when your computer got infected and it prevents you from running Malwarebytes Anti-Malware to clean your PC. It is a freeware malware removal application that's vital.
Here are some screenshots to illustrate the features and user interface of this application:
Emsisoft Anti-Malware
Avast Free Antivirus
AVG Antivirus Free
AVG Internet Security
Trellix Stinger