OneKey founder Yishi issued an urgent warning that iPhone 11 and earlier models contain unpatchable BootROM hardware vulnerabilities (checkm8, usbliter8) that expose stored seed phrases to physical attacks. An attacker with brief device access can exploit DFU mode via a custom USB tool to execute code before the OS boots — rendering airplane mode and factory resets ineffective. Affected devices include iPhone XS, XR, 11 series, and second-generation SE. The attack leaves no visible trace, functioning as a classic "evil maid" scenario. Yishi advised users on these older iPhones to generate an entirely new seed phrase on a secure device and migrate assets immediately, rather than simply restoring backups or creating new addresses under the compromised seed. Additional recommendations include switching from a 6-digit PIN to a long alphanumeric passcode, enabling Lockdown Mode, using personal chargers only, and keeping iOS updated.