Looks like we may have been swept up in this

https://www.trendmicro.com/vinfo/ph/security/news/cybercrime-and-digital-threats/github-hacked-spreads-malicious-syscoin-windows-installers

Sounds exactly like what we were experiencing. 

Needless to say, we've enabled 2fa for all org members and have reset our passwords.

New builds will be available soon.