So I literally just dealt with this crap.
There was a block on Safari claiming that I had to ring this particular number so they could fix it. Safari wouldn't close on its own and had to force quit.
Stupidly I called.. They wanted me to download this file so they could have access to my computer.
They bantered , I ummed and arred for a long time. The man started getting angry and short, guilt tripping me and making me feel bad for the poor choices of websites I had been on ... hahaha
I knew from then it was a scam and called them out on it then his emotional blackmail escalated !
-The difference is Apple has a red arrow and can physically not click into things , they show you where to go with their cursor and you do all the work.
So if you've let them into your computer , turn off wifi , restart in safe mode
Delete the download and get a new malware app.
The Apple assistant recommended malwarebyte. It cleared most of the ****.
I still had to do some searching through the library and delete a few things, all is swell though.
I definitely recommend calling Apple immediately.