Sendgrid Under Siege from Hacked Accounts, rushes to enforce MFA
Email service provider Sendgrid is grappling with an unusually large number of customer accounts whose passwords have been cracked, sold to spammers, and abused for sending phishing and email malware attacks. Sendgrid’s parent company Twilio says it is working on a plan to require multi-factor authentication for all of its customers, but that solution may not come fast enough for organizations having trouble dealing with the fallout in the meantime.
Many companies use Sendgrid to communicate with their customers via email, or else pay marketing firms to do that on their behalf using Sendgrid’s systems. Sendgrid takes steps to validate that new customers are legitimate businesses, and that emails sent through its platform carry the proper digital signatures that other companies can use to validate that the messages have been authorized by its customers. But this also means when a Sendgrid customer account gets hacked and used to send malware or phishing scams, the threat is particularly acute because a large number of organizations allow email from Sendgrid’s systems to sail through their spam-filtering systems.
In an interview with KrebsOnSecurity, Sendgrid parent firm Twilio acknowledged the company had recently seen an increase in compromised customer accounts being abused for spam. While Sendgrid does allow customers to use multi-factor authentication (also known as two-factor authentication or 2FA), this protection is not mandatory.
Neil Schwartzman, executive director of the anti-spam group CAUCE, said Sendgrid’s 2FA plans are long overdue, noting that the company bought Authy back in 2015. “Single-factor authentication for a company like this in 2020 is just ludicrous given the potential damage and malicious content we’re seeing,” Schwartzman said. “I understand that it’s a task to invoke 2FA, and given the volume of customers Sendgrid has that’s something to consider because there’s going to be a lot of customer overhead involved,” he continued. “But it’s not like your bank, social media account, email and plenty of other places online don’t already insist on it.”