Malwarebytes

MalwareBytes isn't really intended for protection. Its main function is to find and remove garbage you've already installed. Not prevent it. It's really the only software of this type just about any experience user on these forums will recommend.

Never install typical AV software such as Norton, Avast, Bitdefener, etc.

If you got it directly from the MalwareBytes site Eau Rouge provided a link to, you may have malware that is intensionally blocking it from running so MalwareBytes can't remove it. Would be far from the first time that's happened.

Boot into Safe Mode by restarting and holding down the Shift key. This takes longer, but you will eventually be asked to login. You will get the login screen even if you have your Mac set to normally login automatically.

Safe Mode only allows very limited processes to load on startup. Meaning, nothing can stop you from running MalwareBytes.

Always a good idea to have Malwarebytes installed so you can keep ahead of adware/ malware.

Hope it still runs on El Capitan. Download the free version.

https://www.malwarebytes.com/mac/

Hello,

It is not necessary to install virus protection, or malware protection, on Macintosh computers.

My Malwarebytes does not open. What shall I do?