I tried to download something from a couple of unfamiliar sites, and I suspect I downloaded something that has infected my Air Mac. Ads keep popping up, new pages suddenly appear telling me I have won some great prize and asking me to click to accept or decline (and when I do neither and try to close the page, I am unable to close it, and therefore had to forcibly shut down my computer. But the same thing keeps happening.).. Sometimes I am suddenly directed to a site which I did not open (e.g. on investments, or a hotel booking site.)
I googled how to clear malware and followed some of the instructions, e.g. "reset settings" in Chrome, or going to my finder to open the Applications folder and delete stuff that I thought was malware, going to the Library folder to delete items which I suspect are malware items etc. Each time I emptied trash and restarted my computer. BUT THE PROBLEM IS STILL THERE!!!
What can I do? Is there any app that I can download to clean up the malware? I am concerned about simply downloading something that turns up on a google search as it might in itself be a malware program. Is there any malware cleanup that I can get for my Mac? Please help! I don't know much about computers :-(