A group of attackers have compromised accounts on the SendGrid email delivery platform and are using them to launch phishing attacks against other SendGrid customers. The campaign is likely an attempt to collect credentials for a mass email service with a good reputation that would help attackers bypass spam filters in other attacks.
“The campaign observed uses a variety of complex lures, such as claiming the victim’s account has been suspended while its sending practices are reviewed or that the victim’s account is marked for removal due to a recent payment failure, combined with other SendGrid features to mask the actual destination of any malicious links,” researchers from threat intelligence firm Netcraft said in a new report.