security question?

Is it possible to have a code pasted somewhere -on my "search page" that redirects me somewhere. I have had alot of problems , I cannot enjoy and play on my computer anymore.yesterday, I got a security certificate name not matching . I looked at it and reported .It wouldnot let me type anything in the search box without this view certificate.not matching. I happen to notice a typed text on the upper corner of the page. (similar) to those post comment codes i use on my favorite website. I am just trying to figure this out.

I havenot been paying attention until recentlly . thought I would ask

is there anysuch thing as people copying and pasting codes on pages without me knowing to redirect me .