Nope, it was autobackup6pro.exe that was quarantined (and removed from my USB stick).
Yes, V6.13.4.31582. Note that a static check (i.e., right-click and check with Defender) doesn't show a problem. The executable was quarantined after the end of a restore job – the restore was finished, Autobackup window still open, then the Defender alert popped up. I can only imagine that Defender detected that autobackup6pro.exe had written many files into personal directories – in other words, the kind of thing that ransomware might do. If that is the cause, it might be difficult to work around it.
I don't have a restore candidate that I can try it on at the moment, but I'll try to put something together later today.