Nothing is perfect and nothing is unbreakable.
Apps reviewed by the App Store are sanitised to ensure they do not call private APIs, and hence can’t get access to most of your private data, specially call and message and email history.
Apps can ask for access to the addressbook, photos, location, but unless you’re tricked into giving them access, they won’t get it.
Apps can’t get access to your mobile information, like Mac addresses, IMEI (ID of the device), IMSI (ID of the SIM card) or MSISDN (your number). Even the UDID is now masked.
There are ways to get bad apps even without jail breaking though:
– if you install an App from outside the Store, either a regular App where the developer asked you for your UDID, or an App from an enterprise developer. If you don’t know and trust the developer, never install anything from external links.
– if the developer gets their computer infected, like it happened with a bunch of Chinese developers and apps, those legit apps may contain unintended functionality. Nevertheless that code can’t do much, besides taking advantage if the legit app already had approval to the addressbook.
There are much much more likely scenarios then having a virus. Try these four steps and see if it resolves your issue:
- Do a “hard” reset: This usually solves most glitches. You can do this by holding down the Home button and the Power button until your screen goes black. To turn your phone back on, simply hold down the power button until the Apple logo appears.
- Install the latest version of iOS: You can do this on the device or on your PC/Mac through iTunes (I recommend doing this through iTunes as it replaces all of the operating system as opposed to patching the updated files). On your phone, go to the Settings app > General > Software Update. If there is an update available, it will let you know and guide you through the process. To do this through iTunes, open the iTunes app, connect your phone, and click on the iPhone logo that pops up in the top. Once you are in there, you will be either presented with a Check for Update button or an Install Update button. Click on whichever one pops up and then let iTunes restore your phone.
- If all else fails, going to the Genius Bar at your local iPhone store or reaching out to Apple Support online is always an option. Here is the link to Apple Support: Official Apple Support