[wasabisashimi]

Hi guys,
I just randomly came across this today.
A few companies has injected malware code inside my webpages.
I can't see them on regular pages, but if I do Ctrl+U in firefox.
I can see 2-3 unwanted codes what has nothing to do with my business and i dont know how it got there in the first place.

These codes include things like viagra, morgage..etc and some complete with an external link.

Is there an explanation to this, and how can I scan my wordpress site to find out what else is there as well as clean-removal of them. I read that each of these shit malware on my pages count as a minus point in my search engine ranking.

I have no training in website making or coding. All I was trying to do was putting in proper meta tags and description.