Why am i recieving fake malware attacks on my computer?

i was sitting on fluther minding my own business, when all of a sudden my computer supposedly gets attacked by somthing..it turns out that the warning is actually the virus..eventually if you let the virus window open up, the virus is stuck there. Any ideas on how to slove this? oh and also..something is preventing me from yielding results from google..like if i searched up guitar tabs, it would take me to a random site advertising shampoo..