My S23 recently died, and I'm thinking about buying a second-hand iPhone to save money. My main concern is privacy and security: after the previous owner signs out and performs a proper factory reset, is the phone essentially as secure as a brand-new iPhone? Is there any realistic chance that spyware or other malicious software could survive the reset? I'd also appreciate advice on what to check when buying one used.
3 Answers
The more practical risks are the seller and the phone’s physical condition, not hidden spyware. Buy from a reputable source, check that Activation Lock is disabled, verify the serial number and battery health, and look for warnings about nongenuine replacement parts. A replaced battery or other third-party component may affect reliability even if the software is secure.
If you want an extra-clean reinstall, you can put the iPhone into recovery mode and restore it from a computer. A DFU restore is generally unnecessary for normal second-hand purchases, but it can provide additional reassurance by reinstalling the operating system.
Yes, assuming the previous owner signed out of their Apple Account and used “Erase All Content and Settings,” the phone should be in a new software state. User data and apps are stored in encrypted areas, and the encryption keys are discarded during the reset. A surviving low-level compromise is theoretically possible but extraordinarily unlikely for an ordinary buyer. Also confirm that Activation Lock is removed before paying.
Thanks, that clears up my main concern. I’ll make sure the old account is removed before buying it.