My elderly aunt just got stung for a few k
Having seen the messages it's quite believable.
'Son' (his name) messages a few days earlier, I've lost my phone, using this number for now, general chit chat building trust.
After a a few days any chance you could pay this invoice for me. Banking app not set up on new phone yet, will pay you back Monday.
You know the rest. Of course have reported to bank/ action fraud etc.
Aunts Facebook profile is private and son doesn't have it so they're not friends on there and can't see any mention of him on there.
How do they get the phone number and more importantly - child's name ? On googling it. It's quite a common scam.