August 2, 2024 at 11:46AM
The EchoSpoofing campaign sent millions of fake emails, exploiting a vulnerability in Proofpoint’s email protection service and Microsoft 365. By using a misconfiguration flaw, the attackers impersonated blue chip companies like Disney and Coca-Cola, exploiting the trust between Microsoft 365 and Proofpoint to send fraudulent emails. Proofpoint implemented a fix, but broader email security questions remain.
From the meeting notes, I have extracted key points and takeaways, summarized below:
Issue:
– Millions of near-undetectable emails impersonating blue chip companies were spread through permissive features in Microsoft 365 and Proofpoint’s email protection service, exploiting a “super-permissive misconfiguration flaw” in Proofpoint’s secure email gateway (SEG).
Operation of “EchoSpoofing”:
– The attacker set up their own Simple Mail Transfer Protocol (SMTP) server to send emails with any “From” header they wished, exploiting a toggle in Proofpoint’s SEG that trusted any emails routed through Microsoft Office 365. It utilized mail exchange (MX) records to target known Proofpoint customers and bypass anti-spoofing technologies like DMARC monitoring.
Impact and Response:
– The EchoSpoofing campaign began in January and continued for several months, reaching millions of fake emails per week despite initial remediation efforts by Proofpoint. After its detection, the attacker showed operational awareness by switching abused domains and Office 365 accounts to stay “under the radar.” The campaign finally died down after Proofpoint introduced a vendor-specific header for outgoing emails.
Lessons Learned:
– Negligence and permissiveness, as well as the lack of secure email controls like DMARC monitoring, contributed to the success of the campaign.
– Companies must implement logging and data tracking for their email distribution to detect anomalies and potential threats.
– The potential for more targeted spear phishing attacks using similar vulnerabilities poses a significant cyber threat.
Overall, the notes illustrate the complexity and severity of the EchoSpoofing campaign, as well as the importance of proactive and secure email practices for organizations.