Get Ad Block for chrome.. Free add-in.

To remove the spam.. Get Malware bytes and run a scan, completely free and has a 99% success rate with removing shit like this. We use it at work because its free ware and does the job better than some paid AV.. (Note, Virus and Spyware are slightly different, so you need protection for both as most AV won't protect from spyware). If you had ad block in chrome, chances are you wouldn't have clicked on the link that infected your computer anyways..

Good luck