Ultimatesafeguard.com is a new malicious site. Ultimatesafeguard.com displays many fake alerts that try to make you download and install some potentially unwanted applications. Don't interact with such pop-ups. They are fake and deceptive. Get rid of them with Combo Cleaner Antivirus via the official page -
https://www.combocleaner.com or, optionally, follow the manual recommendations provided in the video.