Credentials for more than 225,000 Apple accounts have been stolen by sophisticated malware that targets modified iOS devices. The malware enables attackers to download applications from Apple’s App Store without paying or to lock devices in lieu of a ransom.

Jailbreaking removes Apple’s protections that limit what apps can be installed on a device. Apple advises against jailbreaking for security reasons. The malware has been spread by being incorporated into jailbreak tweaks, or software packages that allow for some new function to be run on iOS. The malware has been found within tweaks published on the Weiphone forum for jailbroken phones.