add/spyware

I have a problem..

my sister often listens to music on the net..but I get ads from the site she goes to.

Only I can't prove it..Is there a spyware software or ads software, which will block the sites where the adds come from, after deleteting the ads.

I mean, after scanning and deletting the software will actually show what the source was, and then blocking the site permanently.
If I have pay for the software I will..Im desperate

Thanks in advance