They are apparently onto the VM trick now. I've heard of them checking the running processes for the virtualized network connection, etc.
There's a twitch streamer called Kitboga that messes with these types of scammers in VMs. It's pretty entertaining. He uses a voice changer and has a timer in the corner on how long he manages to keep a scammer occupied.
Their initial contact
https://www.troyhunt.com/anatomy-of-virus-call-centre-scam/
When he called them back
https://www.troyhunt.com/scamming-scammers-catching-virus-ca...