More than 225,000 iPhone accounts have been hacked by through the Cydia app since July 2015, according to CNN. The theft is being called the "largest known Apple account theft caused by malware" by security company Palo Alto Networks, the company that discovered the hack with the help of Chinese tech group WeipTech. A statement was released on Sunday.

The hack, which is nicknamed KeyRaider, is only effective against jailbroken devices, a common procedure that allows iPhone owners to take advantage of the phone's file systems that are typically not accessible. It was distributed through Cydia, one of the most popular tools for jailbreaking iPhones. Although the hack is most common on Chinese websites and apps, it has spread to 18 other countries, including the United States, Japan, France and Australia.

Login details, purchasing receipts and device IDs are just some of the data that were stolen from victims of the hack, according to The Telegraph. Those with jailbroken devices can check if they've been affected by the hack by checking their app purchasing history - those who have been hit will have an abnormal history, according to Burton Mail.

The best way to avoid the hack is using a phone that is not jailbroken. Jailbreaking is achieved using unauthorized tools and is not approved by Apple - it also increases your phone's susceptibility to malware, as evidenced by this case.