For most of the iPhone’s lifespan, it’s been effectively immune to malware. There were theoretical attacks and viruses targeting jailbroken phones, but thanks to the tight controls of the App Store, finding iOS malware in the wild has been nearly impossible. If you didn’t jailbreak your phone and you weren’t targeted by the NSA, you simply didn’t have to worry about catching a virus.

A pernicious piece of Apple-focused malware reared its ugly head this week. It may have infected as many as 356,000 users. All are based in China, where the malicious WireLurker code was hidden inside 467 OS X applications on the unofficial Maiyadi App Store. The malware first infects Mac OS X machines, from standard desktop Macs to MacBooks, and then infiltrates all other iDevices, from iPhones to iPads, by installing rogue apps on them when they’re connected by USB. And unlike previous strains of iOS malware, it doesn’t need the device to be jailbroken. Palo Alto Networks, the company that has investigated and given a name to WireLurker, calls it a “new breed of threat to all iOS devices”. Qū Chāo, a developer at Tencent, initially observed WireLurker at the start of June.