What can possibly go wrong with that iPhone? I’ll have a look (oh, it’s locked!), then switch it off, eject the SIM card and pass it on to the expert. Well, you’ve just made three of the five most common mistakes making subsequent unlock and extraction attempts significantly more difficult. Learn about the most common mistakes and their consequences.
What is DFU, and how is it different from the recovery mode? How do you switch the device to recovery, DFU or SOS mode, what can you do while in these modes and what do they mean in the context of digital forensics? Can you use DFU to jailbreak the device and perform the extraction if you don’t know the passcode? Read along to find out.
For us, this year has been extremely replete with all sorts of developments in desktop, mobile and cloud forensics. We are proud with our achievements and want to share with you. Let’s have a quick look at what we’ve achieved in the year 2019.
The past two years introduced a number of challenges forensic experts have never faced before. In 2018, Apple made it more difficult for the police to safely transport a seized iPhone to the lab by locking the USB port with USB restricted mode, making data preservation a challenge. The release of the A12 platform, also in 2018, made it difficult to unlock iOS devices protected with an unknown password, while this year’s release of iOS 13 rendered unlock boxes useless on iPhones based on the two most recent platforms.
Passwords are probably the oldest authentication method. Despite their age, passwords remain the most popular authentication method in today’s digital age. Compared to other authentication mechanisms, they have many tangible benefits. They can be as complex or as easy to remember as needed; they can be easy to use and secure at the same time (if used properly).
The Screen Time passcode is an optional feature of iOS 12 and 13 that can be used to secure the Content & Privacy Restrictions. Once the password is set, iOS will prompt for the Screen Time passcode if an expert attempts to reset the device backup password (iTunes backup password) in addition to the screen lock passcode. As a result, experts will require two passcodes in order to reset the backup password: the device screen lock passcode and the Screen Time passcode. Since the 4-digit Screen Time passcode is separate to the device lock passcode (the one that is used when locking and unlocking the device), it becomes an extra security layer effectively blocking logical acquisition attempts.
With over half a million users, Signal is an incredibly secure cross-platform instant messaging app. With emphasis on security, there is no wonder that Signal is frequently picked as a communication tool by those who have something to hide. Elcomsoft Phone Viewer can now decrypt Signal databases extracted from the iPhone via physical (well, file system) acquisition, and that was a tough nut to crack.
The Screen Time passcode (known as the Restrictions passcode in previous versions of iOS) is a separate 4-digit passcode designed to secure changes to the device settings and the user’s Apple ID account and to enforce the Content & Privacy Restrictions. You can add the Screen Time passcode when activating Screen Time on a child’s device or if you want to add an extra layer of security to your own device.
By this time, seemingly everyone has published an article or two about Apple re-introducing the vulnerability that was patched in the previous version of iOS. The vulnerability was made into a known exploit, which in turn was used to jailbreak iOS 12.2 (and most previous versions). We’ll look at it from the point of view of a forensic expert.
What can and what cannot be done with an iOS device using Touch ID/Face ID authentication as opposed to knowing the passcode? The differences are huge. For the sake of simplicity, we’ll only cover iOS 12 and 13. If you just want a quick summary, scroll down to the end of the article for a table.