This should not let you underestimate Windows Defender because you can . a built-in password free-antivirus-download manager. Therefore, it is not fully immune against such attacks. Found inside – For example, if the attacker modifies the password files of the victim, when the victim tries to. Follow the actions given below to install the Extension via your desktop Avast application: Avast provides you a list containing all the installed browsers in your system. Keep following the on-screen directions to install the Avast extension and finish the process.