The FBI warned private industry partners of threat actors abusing Microsoft Office 365 and Google G Suite as part of Business Email Compromise (BEC) attacks. The FBI issued a number of defense recommendations IT admins can implement on their networks to prevent BEC attacks. Cybercrime was behind individual and business losses of $1.8 billion during the last year alone. The IC3 also issued a Public Service Announcement (PSA) in September 2019 warning that BEC scams are continuing to grow every year.
Source: https://www.bleepingcomputer.com/news/security/fbi-warns-of-bec-attacks-abusing-microsoft-office-365-google-g-suite/