Hardware crypto wallet maker Trezor is warning customers for the second time in as many months that one of the companies it relies on was hacked, exposing the data of Trezor’s customers to hackers.

In a blog post this week, the hardware wallet maker said a cyberattack on Brevo, a marketing tech company that Trezor uses to send newsletters, allowed hackers to send around 347,000 phishing emails to Trezor customers with a malicious link purporting to come from the wallet maker.

The link, when tapped, downloads an app that asks the victim for their wallet backup password. According to Trezor, one of the email subject lines said: “Critical Security Alert: STM32 Entropy Vulnerability.” 

With a stolen wallet password, a…