Trezor and BitBox warned users on Sept. 9 about phishing emails impersonating their brands and urged recipients not to follow the messages' links or instructions. Trezor said a third-party email provider had been breached, identified the email titled "Critical Security Alert: STM32 Entropy Vulnerability" as fraudulent, took down the related domain and investigated how attackers accessed its legitimate domain. On Sept. 10, it reiterated that its wallets remained safe. BitBox said its preliminary review found it very likely that its newsletter provider had been compromised, adding that other Bitcoin companies appeared to have been targeted through the same provider. BitBox notified newsletter subscribers, contacted the provider and reported phishing domains; most links had been taken down as its investigation continued. Users should keep their recovery seed (wallet backup words controlling funds) private, avoid suspicious links and attachments, and obtain follow-up information only through official company channels and the official Trezor Suite website.