I've been very happy with CleanMyMac.

Malwarebytes and CCleaner are 2 that I use. I don't know if they'll take care of the Search Marquis or not.

My iMac has been terribly slow. I use Chrome & Firefox, mainly FF. I had to turn off most of the add on's that were on FF.

I also need to update to the most recent version, but I do NOT want to give up MS Word!!!

I did a quick Google search and Marquis is a malware product. Goto Apple and there are instructions on how to remove and repair your system. Do you have a recent backup from before your computer was hijacked? If so I would just use the backup and restart from a date before the problems started.

Do you have Apple Care? I would call Apple and let them walk you through the process.

Thanks everyone! I tried to remove the malware myself by following a complicated set of instructions. It was still there so I bought a year subscription to CleanMyMac. it’s running smoothly now and I can scan it regularly.

I've never done this before-but sounds like I need too. Regarding the CleanMyMac, do you just buy the subscription and run it? Do I need to back up my computer first? What does it get rid of? Sorry for all the questions.

Olliesmom, there is a free subscription option but I bought the paid one instead. you get a code and simply put it in the box. It scans for lots of things and will tell you to quit a program if it needs it to close. Also checks for speed, memory, efficiency etc.

Yes, get the paid one. I'm very happy with it.