Trezor: 347,000 users targeted in phishing attacks after Brevo breach

Summary

Trezor has disclosed that a phishing campaign targeting 347,000 of its customers originated from a breach of its third-party email provider, Brevo. Threat actors gained access to Brevo's systems and used it to send fake security alert emails to Trezor customers, tricking 2,500 into clicking malicious links and downloading a fake app. Trezor has since suspended the Brevo account and taken down the phishing domain.

Full text

Trezor: 347,000 users targeted in phishing attacks after Brevo breach By Sergiu Gatlan September 11, 2026 03:55 AM 0 Trezor has revealed that phishing attacks against its customers earlier this week targeted 347,000 email addresses and affected 2,500 users who clicked an embedded malicious link. As Trezor warned on Wednesday, threat actors who breached Brevo, its third-party email provider, were emailing customers who opted in to receive newsletters. According to customers targeted in this phishing campaign, they received fake "critical security alert" emails from help@trezor.io claiming that a "hardware microcontroller vulnerability" in Trezor cold storage wallets' STM32 microcontrollers could expose their seeds to brute-force cracking. The phishing emails tried to trick recipients into clicking a malicious link that prompted them to download an app that asked them to enter their wallet backup. Trezor says that it took down the domain used in the phishing attacks within 20 minutes, disabling the link and limiting the campaign's impact to 2,500 customers who had clicked it before it was taken down. "On September 9, 2026, Brevo, the third-party marketing platform Trezor uses for newsletter campaigns, suffered a security incident affecting 120 Brevo accounts. An unauthorized actor gained access to Brevo's system and used it to send emails from various customer accounts, including Trezor's," the company said. "The incident affected our opt-in newsletter database, roughly 347,000 email addresses. These addresses might be potentially used for other phishing attacks in the future. No other Trezor system was touched. We have suspended the Brevo account to stop further email distribution." Trezor phishing email (Geo Soul) In January 2024, Trezor disclosed another data breach after its third-party support ticketing portal was hacked and attackers stole data (including names, usernames, and email addresses) from roughly 66,000 users. Trezor also disclosed a data breach last month after threat actors hacked ShipMonk, its logistics and shipping provider, using a critical Metabase SQL injection zero-day vulnerability, and stole customers' order data, including full names, shipping addresses, email addresses, and phone numbers. While Trezor initially said the incident affected nearly 14,000 customers, a follow-up investigation found that the resulting breach affected an additional 67,000 U.S. customers, bringing the total to 81,000 individuals. The company said that the incident also affected customers in Brazil, Colombia, Italy, Portugal, Sweden, and the United Kingdom who received orders between May 10 and August 8, 2026. Since then, BleepingComputer also learned that ShipMonk received extortion emails from the ShinyHunters extortion gang following the breach. Build your security blueprint for AI-powered attacks Join Mikko Hyppönen and security leaders from the NFL, CHANEL, and Atlassian for a two-hour digital summit on what AI-speed attacks change, what defenders should stop doing, and how to validate, decide, fix, and re-validate at machine speed. Save your seat Related Articles: Trezor warns users of email provider breach, phishing attacksThe Top 4 Threats We Found by Investigating Every Alert for a QuarterMan gets six years for hacking 750 women's Snapchat accountsShinyHunters extortion gang claims Odido breach affecting millionsBigBear Microsoft 365 phishing service bypassed MFA at 258 organizations

Indicators of Compromise

• email — help@trezor.io

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