Microsoft disrupted a large-scale business email compromise (BEC) campaign that used forwarding rules to access messages related to financial transactions. The attackers breached the mailboxes of the victims using phishing messages, then exfiltrated sensitive data contained in the incoming messages using matching forwarding rules. The FBI 2020 annual report on cybercrime for 2020 listed a record number of more than $1.8 billion adjusted losses reported last year. External email forwarding is now disabled by default in Office 365, significantly reducing the threat of BEC campaigns.”]
Source: https://securityaffairs.co/wordpress/118958/cyber-crime/microsoft-disrupted-bec-campaign.html