Trezor warns users of email provider breach, phishing attacks

Cryptocurrency hardware wallet maker Trezor warned customers on Wednesday that threat actors who breached its third-party email provider are targeting them in phishing attacks.

Affected customers received fake "critical security alert" emails from [email protected] claiming that a "hardware microcontroller vulnerability" in the STM32 microcontrollers used by Trezor cold storage wallets could expose their seeds to brute-force cracking.

The company said that it's investigating the breach and that the domain has been taken down to stop the attacks.

"Our third-party e-mail provider has been breached. Please be aware that the email named 'Critical Security Alert: STM32 Entropy Vulnerability' is not coming from us, and it's a phishing attempt. Do not click on any link," Trezor warned.

"We have taken down the domain, and we are investigating the situation, including how the hackers got access to our legit domain."

​Trezor also disclosed a data breach in August after attackers hacked ShipMonk, its shipping and logistics provider, and stole customers' order data, including full names, shipping addresses, email addresses, and phone numbers.

While the company initially said the incident affected nearly 14,000 customers, a Friday update warned that a follow-up investigation found the breach affected an additional 67,000 U.S. customers, bringing the total to 81,000.

As Trezor explained, the data breach also impacted customers in Brazil, Colombia, Italy, Portugal, Sweden, and the United Kingdom who received orders between May 10 and August 8, 2026. While it didn't say how ShipMonk's systems were breached, breach notification emails seen by BleepingComputer said the attackers exploited a vulnerability in the Metabase analytics platform.

In early August, Metabase said the threat actors exploited a critical SQL injection zero-day vulnerability to breach customer instances, gain administrator access, and steal data.

BleepingComputer has also learned that ShipMonk received extortion emails from the ShinyHunters extortion gang after the breach.

In January 2024, Trezor disclosed another data breach after its third-party support ticketing portal was compromised and the attackers accessed data (e.g., names, usernames, and email addresses) from roughly 66,000 users.