Full System Scan and Power Eraser came up with nothing. So I seem to have had it for a while, but it's just recently seemed to actually do something. It used to be that every now and then it redirects me, maybe around once every couple weeks, but now it's doing it quite often. It sometimes redirects and sometimes opens up a new page upon clicking something, as well as what I clicked on.
It's worth noting that I had previously been infected with Malicious File Download 12, I assume they're related.