Adware in Safari, No VSearch Folder

After a few years of owning my Air, I suddenly have Adware/Malware in Safari and can't seem to get rid of it. I don't know why. A bunch of words are highlighted in blue and every single time I click on anything (not the highlighted words, obviously. Just my regular stuff) a new tab opens with spam. I've read other forums on this site and they suggest searching finder for VSearch folders/files. Mine has none. Can anyone help me figure out what is going on?

I don't often download applications to my computer and I'm super skeptical of anti-virus software downloads, so I don't know what to do or what services to trust.

Advice is appreciated.