Crypto customers targeted by scammers after email marketing provider breach

An attacker breached an email marketing platform and launched targeted attacks against the newsletter subscribers of some of its customers, especially those working in cryptocurrency and adjacent fields.

The incident was a supply-chain phishing campaign carried out through Brevo, an email marketing provider used by several cryptocurrency companies and other firms.

Brevo initially said an attacker had gained access to 120 customer accounts, some of which were used to send phishing emails to the customers’ contact lists.

Brevo later said 138 customer accounts had been accessed in its postmortem:

“On September 10th at 6:30 AM UTC we identified a security issue where an attacker exploited a flaw in the way Brevo handles SAML SSO to gain access to 138 Brevo accounts. 6 of those accounts were used to send phishing emails to the contacts stored there, and for 43 accounts they exported the contacts. 93 accounts have no meaningful activity.”

According to reports, popular cryptocurrency companies Trezor, CoinTracking, and BitBox confirmed that phishing emails were sent to customers subscribed to their newsletters. Trezor warned its roughly 347,000 newsletter subscribers that a security incident at a third-party provider had resulted in a massive phishing campaign.

Trezor makes hardware wallets that store cryptocurrency private keys offline. Its customers received a phishing email titled “Critical Security Alert: STM32 Entropy Bug Identified.”

The subtitle read: “Urgent update regarding hardware microcontroller vulnerability.”

The email said: