how to eliminate https://validate.perfdrive.com from safari

Consider downloading and running this little "discovery" utility, Etrecheck. It changes NOTHING. Etrecheck was developed by a senior contributor here, and uses mostly system calls and simple tests to collect often-needed information.

it contains little tests for speeds of devices, CPU utilization, memory usage, energy usage and a digest of recent problems, in one easy to use package. it does not even need to be Installed. Because less can be learned when your Mac is running great, best time to run is when your problems are actually occurring, if possible.

if you follow the directions faithfully, its report (pre-laundered of all personally-identifiable information) can be "Shared" to the System ClipBoard, then Pasted into an ‘Additional Text’ window in a reply on the forums.

Use Etrecheck Pro for free:

http://Etrecheck.com

The amount of data you get can be daunting. If you POST your report, some Readers here are willing to look over those reports, and can provide valuable insights.

Then start a reply on the forums, click the "additional text" icon and PASTE

You may have 'accidentally' set your start page to that web site.

Safari > settings > General ...

check each box and make sure all defaults are to your liking

what third-party anti-virus software have you added?

Have you tried Quitting Safari and re-launched while holding the Shift key, to keep previous web sites from loading? Maybe it's some diabolical thing in a hidden window.