redirect to virus scam - said to call Apple support at a bogus number

[toyglass4me]

Typed in "Ebay" Chrome and before the Ebay web site even opened it redirected to a message that my Mac computer was infected. It gave a bogus number, so knew it was a scam.  How ca I stop this? It doesn't happen on any other site.

[beyondthetreeline]

"before the Ebay web site even opened it redirected"

Sorry, but this is user error. You selected what link appeared from Chrome. Need to look more carefully, or try an alternative browser.

[wesk_36]

Browser hijacker malware is the most common cause.

Typically, they change the homepage and default search settings. 

But some are known to inject advertisements, like the fake one you described.

A antivirus scan, or a program like Malwarebytes Free, for instance, can  clean your computer of the redirect virus, if that's the cause.

I had something like this many years ago, I think it came bundled in a software download.

[wesk_36]

Here is another article that may interest you;

https://www.myantispyware.com/2018/10/25/how-to-remove-virus-alert-from-apple-pop-up-scam-from-mac/