Strange day: Has there been a high number hacks going on or what? Niece got hit with Adware and someone tried to order a

[silvarios]

Yeah, that's a phishing attack. Two thoughts, after your niece called them, they might have been looking to immediately install malware or alternately install remote access in order to have later opportunities for mayhem.

I'd nuke and pave and reinstall from a backup, assuming there's a proper backup for any necessary files (you mentioned Time Machine so fingers crossed). Potentially no worries, but to be on the safe side, might be best to consider changing any stored passwords as well.

In all honesty, malware program or not, nuke and pave is the safest best, then a malware scan after you reload the files from backup just in case.