If this isn’t a virus, then what is it?
I have been a reader of MacFormat for many years. Ironically, I have just had a request for renewal which I have not been able to fulfil due to a pop-up message. I’ve always understood that Macs don’t have viruses, and I’ve seen no articles suggesting what to do if you actually get one. My MacBook Pro running Yosemite now seems riddled with problems: I see many pop-ups, to the point that it’s virtually impossible to order online due to ads promoting software (supposedly for OS X) to clean the computer. Every so often I’m told to upgrade Flash (I haven’t). Do you recommend any software to help with any of these problems? David Hurn No. Downloading utilities to clean your Mac is actually a common way to acquire this stuff in the first place. It’s called adware, and it’s an example of a Potentially Unwanted Program (PUP). It’s important to understand that these aren’t viruses or worms, because they aren’t selfreplicating. To install them you will have had to click a download link on a web page and then click OK on the dialog that pops up to warn that you’re installing software from the web. Figuring out what is safe and what isn’t on the web is a bit like figuring out which are the safe streets to walk down late at night in a big city. It’s a hard thing to teach and a lot of it comes down to having a ‘spidey sense’ for things that look suspect.
My dad, for example, is terrible at this and will be wildly paranoid about things that are quite safe, yet blithely end up downloading all sorts of stuff that takes me ages to get rid of. If your web fu isn’t powerful enough to keep you out of trouble, the safest thing is to only download apps from the Mac App Store. Back this up by ensuring ‘Allow apps downloaded from‘ in Security & Privacy preferences is not set to Anywhere.
Getting rid of the adware is just a question of dragging the appropriate folders into the Trash and resetting the search engine and Homepage settings in Safari’s preferences. There’s a good list of folders that common adware uses at http://apple.co/1TzQD4V.