That is definitely malware, so you must of downloaded something fishy, installed it and along with it came the malware. so even if you remove the extensions etc from chrome it will still be there, you need to get the free trial of malwarebytes, do a scan and it will remove it. just remember , dont click the links on the "pc repair site", what will ensue will just be more malware and probably a virus, or even cryptolocker, which can and will irreversibly erase the entire hard drive top to bottom.
