On my iPhone (iOS 8.2), I installed an app that wasn't coming from the App Store. I chose to trust it because a serious news website had spoke about it, but now I'm a little bit worried of what this app might have done.

Are the apps like this one still prevented from accessing my personal content?
Could they install anything without my authorization?
Now that I've deleted it, is it okay or is there still a risk anyway?


With the improved Masque attack, it is possible to perform many actions, including full kernel and user memoryspace traversal, which would include any sort of temporary or permanent backdoor against jailed iOS, including version 8.2 (i.e., this does not require a jailbroken device). When combined with a shim, this can be a devastating attack against other previously-installed apps, perhaps even without memoryspace access. Futher combined with OS X DLL hijacking (another new attack), things get really clever.

Today, as of March 2015, nearly anything is possible. The entire security of the iOS platform has been undone due to Enterprise certificate attacks (i.e., improved Masque), repackaging apps (e.g., Theos), library shimming (i.e., the load operation), and lazy binding abuse. This could lead to function hooking on a jailed device, which could lead to subversion of many concepts, including subversion of the KeyChain, TouchID, and much more than forensics tools are currently capable of (even assuming a lockdown certificate is set and no recoverable lockdown cert or backup is possible on, say, jailed iPhone 6 with iOS 8.2).


Apps not from the app store are not as safe but they still can't access any of your information without your consent. The chances they would install malware is slim because iPhones are very secure. Though it is less popular, side loading apps from your computer is a lot more risky as there are no checks in place to protect your phone. Once you have deleted the app you are definitely safe.

  • Thank you ! And they can't install malwares? How about the Massive Attack breach ? – Trevör Mar 24 '15 at 16:05
  • I've changed the answer to include the information. – pjtnt11 Mar 24 '15 at 16:10
  • 3
    What method did you use to install an app, bypassing the app store? iPhones are relatively secure with Apple-issued iOS installations and apps sourced from the App Store, but you're moving into uncharted territory as soon as you jailbreak a device and use apps which haven't been subject to scrutiny by Apple. It's unwise to assume your information is safe if you've bypassed Apple's security measures to install an app, and you can be sure of one thing - anyone targeting the iPhone to deploy malware is going to have an easier time offering freebies for jailbroken devices. – ScunnerDarkly Mar 24 '15 at 17:01
  • "Apps not from the app store are not as safe"? I disagree with that. – Zizouz212 Mar 26 '15 at 21:40
  • @ScunnerDarkly no, I haven't goat a jailbroken device but I downloaded from a link – Trevör Mar 27 '15 at 18:21

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