Hmm… I enabled PUP in avast settings and re-scanned the file.
Still “no threat found”

Ahh… update:
As the file was 700mb, I could not use any of the online scanners.
However, I just zipped the file and it shrank to under 1mb…
Now I am getting some positive matches on virustotal:
AVG Luhe.Fiha.A
Baidu Archive.Bomb
DrWeb Trojan.PWS.Multi.911
ESET-NOD32 a variant of MSIL/Injector.CVJ
Ikarus Trojan-Spy.MSIL
Invincea worm.msil.mofin.a
Sophos Troj/dnCreek-A
VBA32 suspected of ZIP.MailBomb

But still 50 AV companies are finding nothing.