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iOS 12 Enhances USB Restricted Mode

Thursday, September 20th, 2018

The release of iOS 11.4.1 back in July 2018 introduced USB Restricted Mode, a feature designed to defer passcode cracking tools such as those developed by Cellerbrite and Grayshift. As a reminder, iOS 11.4.1 automatically switches off data connectivity of the Lightning port after one hour since the device was last unlocked, or one hour since the device has been disconnected from a USB accessory or computer. In addition, users could manually disable the USB port by following the S.O.S. mode routine.

iOS 12 takes USB restrictions one step further. According to the new iOS Security guide published by Apple after the release of iOS 12, USB connections are disabled immediately after the device locks if more than three days have passed since the last USB connection, or if the device is in a state when it requires a passcode.

“In addition, on iOS 12 if it’s been more than three days since a USB connection has been established, the device will disallow new USB connections immediately after it locks. This is to increase protection for users that don’t often make use of such connections. USB connections are also disabled whenever the device is in a state where it requires a passcode to re-enable biometric authentication.”

Source: Apple iOS Security, September 2018 (more…)

Cloud Forensics: Why, What and How to Extract Evidence

Thursday, September 6th, 2018

Cloud analysis is arguably the future of mobile forensics. Whether or not the device is working or physically accessible, cloud extraction often allows accessing amounts of information far exceeding those available in the device itself.

Accessing cloud evidence requires proper authentication credentials, be it the login and password or credentials cached in the form of a binary authentication token. Without authentication credentials, one cannot access the data. However, contrary to popular belief, even if proper authentication credentials are available, access to evidence stored in the cloud is not a given. In this article we’ll tell you how to access information stored in Apple iCloud with and without using forensic tools. (more…)

Analysing Apple Pay Transactions

Thursday, August 30th, 2018

With more than 127 million users in multiple countries, Apple Pay is one of the more popular contactless payment systems. Unlike some competing payment technologies, Apple Pay is not only tightly integrated into Apple’s ecosystem but is exclusive to Apple devices.

Apple Pay serves as a digital wallet, digitizing user’s payment cards and completely replacing traditional swipe-and-sign and chip-and-PIN transactions at compatible terminals. However, unlike traditional wallets, Apple Pay also keeps detailed information about the user’s point of sale transactions. Due to the sheer amount of highly sensitive information processed by the system, Apple Pay is among the most securely protected vaults in compatible devices. In this article we’ll show you where and how this information is stored in the file system, how to extract it from the iPhone and how to analyse the data. (more…)

Using Intel Built-in Graphic Cores to Accelerate Password Recovery

Tuesday, August 14th, 2018

GPU acceleration is the thing when you need to break a password. Whether you use brute force, a dictionary of common words or a highly customized dictionary comprised of the user’s existed passwords pulled from their Web browser, extracted from their smartphone or downloaded from the cloud, sheer performance is what you need to make the job done in reasonable time.

Making use of the GPU cores of today’s high-performance video cards is not something one can ignore. A single video card such as an NVIDIA GTX 1080 offers 50 to 400 times the performance of a high-end, multi-core Intel CPU on some specific tasks – which include calculations of cryptographic operations required to break encryption and brute-force passwords. The benefits are very real:

But what if you don’t have immediate access to a computer with a dedicated high-end video card? What if you are working in the field and using a laptop with its video output handled by Intel’s built-in graphic chip?

We have good news for you: you can use that built-in Intel chip to speed up password attacks. Granted, a power-sipping Intel chip won’t give you as much performance as a dedicated board dissipating 200W of heat, but that extra performance will literally cost you nothing. Besides, many ElcomSoft tools such as Elcomsoft Distributed Password Recovery will simply add that extra GPU chip to the list of available hardware resources, effectively squeezing the last bit of performance from your PC. (more…)

Android Pie Lockdown Option: a Match for iOS SOS Mode?

Wednesday, August 8th, 2018

We have already covered the emergency SOS mode introduced in iOS 11. When entering this mode, the phone disables Touch ID and Face ID, requiring the passcode to unlock the phone. It appears that Google is taking cues from Apple, adding a new Lockdown Option to the newly released Android 9 Pie. Let us see what is similar and what is different between iOS SOS mode and Android 9.0 Pie Lockdown Option.

(more…)

Accessing Lockdown Files on macOS

Thursday, July 12th, 2018

Lockdown records, or pairing records, are frequently used for accessing locked iOS devices. By using an existing lockdown record extracted from the suspect’s computer, forensic specialists can perform logical acquisition of the iOS device with iOS Forensic Toolkit and other forensic tools. Logical acquisition helps obtain information stored in system backups, access shared and media files, and even extract device crash logs. However, lockdown records may be tricky to access and difficult to extract. macOS protects lockdown files with access permissions. Let’s find out how to access the lockdown files on a live macOS system.

What Are Lockdown Records, Technically?

A down to the Earth explanation of a lockdown records is it’s simply a file stored on the user’s computer. More technically, lockdown files keep cryptographic keys that are used to allow iOS devices communicate with computers they are paired to. Such pairing records are created the first time the user connects their iOS device to a Mac or PC that has iTunes installed. Lockdown records help the iPhone talk to the computer even if the iPhone in question is locked, so that the user does not have to unlock the device every time it’s connected to the PC. This means that experts may be able to perform logical acquisition of locked iOS devices if they can obtain a valid, non-expired lockdown record. There are some “ifs and buts” though. Namely, lockdown records expire after a while. And you can only use lockdown records if the iPhone in question was unlocked (with its passcode) at least once after it was powered on or rebooted. Otherwise, the data partition remains encrypted, and you can access very little information (yet you can still get some info about the device).

macOS Protects Access to Lockdown Files

In macOS, lockdown records are stored at /private/var/db/lockdown. Starting with macOS High Sierra, Apple restricts access to this folder. If you are analyzing a live system, you’ll need to manually grant access rights to this folder. This is how.

(more…)

Training in Vienna

Tuesday, July 10th, 2018

Did you know we have forensic trainings? We’ve partnered with T3K Forensics to feature a 3-day training on iOS forensics. This fall in beautiful Vienna, 17.-19.10.2018, we’ll train a group of law enforcement and forensic specialists on every aspect of iOS acquisition and analysis. We’ll talk about the acquisition workflow and have participants perform logical, physical and cloud extraction of iOS devices. Expect live demonstrations and fully guided hands-on experience jailbreaking and extracting iOS devices, pulling data from locked iPhones and accessing the cloud for even more evidence.

In this training:

  • Mobile acquisition workflow
  • Seizing, storing and transporting wireless capable mobile devices
  • Acquisition methods that don’t work
  • Full-disk encryption, passcode and biometrics
  • Acquisition methods: logical, physical and cloud
  • Logical acquisition: extracting encrypted and unencrypted backups; shared files; photos and videos; crash logs
  • Logical acquisition of locked devices: locating, extracting and using lockdown records
  • Physical acquisition: jailbreaking, imaging the file system, extracting passwords and decrypting the keychain
  • Cloud acquisition: synced data; backups; messages; iCloud Keychain (Safari passwords)

(more…)

Using iOS 11.2-11.3.1 Electra Jailbreak for iPhone Physical Acquisition

Tuesday, July 10th, 2018

It’s been fast. iOS 11.3.1 and all earlier versions of the system down to iOS 11.2 have been successfully jailbroken. In addition, the jailbreak is compatible with iOS 11.4 beta 1 through 3. We normally wouldn’t post about each new jailbreak release; however, this time things are slightly different. The new Electra jailbreak uses two different exploits and presents two very different installation routines depending on whether or not you have a developer account with Apple. Considering how much more stable the developer-account exploit is compared to the routine available to the general public, this time it pays to be an Apple developer.

We tested the Electra jailbreak and can confirm that iOS Forensic Toolkit 4.0 is fully compatible. File system imaging and keychain extraction work; no OpenSSH installation required as Electra includes an SSH client listening on port 22.

Why Jailbreak?

For the general consumer, jailbreak is one open security vulnerability calling for trouble. Apple warns users against jailbreaking their devices, and there is much truth in their words.

Forensic experts use jailbreaks for much different reasons compared to enthusiast users. A wide-open security vulnerability is exactly what they want to expose the device’s file system, circumvent iOS sandbox protection and access protected data. Jailbreaking extract the largest set of data from the device. During jailbreaking, many software restrictions imposed by iOS are removed through the use of software exploits.

In addition to sandboxed app data (which includes conversation histories and downloaded mail), experts can also extract and decrypt the keychain, a system-wide storage for online passwords, authentication tokens and encryption keys. Unlike keychain items obtained from a password-protected local backup, physical extraction of a jailbroken device gains access to keychain items secured with the highest protection class ThisDeviceOnly (this is how).

The New Electra Jailbreak

Jailbreaking iOS versions past 11.1.2 (for which a Google-discovered vulnerability was published along with a proof-of-concept tool) was particularly challenging but not impossible. At this time, a team of jailbreakers discovered not one but two different vulnerabilities, releasing two versions of Electra jailbreak. Why the two versions?

(more…)

This $39 Device Can Defeat iOS USB Restricted Mode

Monday, July 9th, 2018

The most spoken thing about iOS 11.4.1 is undoubtedly USB Restricted Mode. This highly controversial feature is apparently built in response to threats created by passcode cracking solutions such as those made by Cellerbrite and Grayshift. On unmanaged devices, the new default behavior is to disable data connectivity of the Lightning connector after one hour since the device was last unlocked, or one hour since the device has been disconnected from a trusted USB accessory. In addition, users can quickly disable the USB port manually by following the S.O.S. mode routine.

Once USB Restricted Mode is engaged on a device, no data communications occur over the Lightning port. A connected computer or accessory will not detect a “smart” device. If anything, an iPhone in USB Restricted Mode acts as a dumb battery pack: in can be charged, but cannot be identified as a smart device. This effectively blocks forensic tools from being able to crack passcodes if the iPhone spent more than one hour locked. Since law enforcement needs time (more than one hour) to transport the seized device to a lab, and then more time to obtain an extraction warrant, USB Restricted Mode seems well designed to block this scenario. Or is it?

We performed several tests, and can now confirm that USB Restricted Mode is maintained through reboots, and persists software restores via Recovery mode. In other words, we have found no obvious way to break USB Restricted Mode once it is already engaged. However, we discovered a workaround, which happens to work exactly as we suggested back in May (this article; scroll down to the “Mitigation” chapter).

(more…)

Apple Warns Users against Jailbreaking iOS Devices: True or False?

Monday, July 2nd, 2018

Apple has an article on their official Web site, warning users against jailbreaking iOS devices. The article “Unauthorized modification of iOS can cause security vulnerabilities, instability, shortened battery life, and other issues” is available at https://support.apple.com/en-us/HT201954. How much truth is in that article, and is jailbreaking as dangerous as Apple claims? We’ll comment the article based on our extensive experience in jailbreaking more than a hundred devices running every version of iOS imaginable.

Security Vulnerabilities

Apple introduces the concept of jailbreaking by stating the following: “iOS is designed to be reliable and secure from the moment you turn on your device. Built-in security features protect against malware and viruses and help to secure access to personal information and corporate data. Unauthorized modifications to iOS (also known as “jailbreaking”) bypass security features and can cause numerous issues to the hacked iPhone, iPad, or iPod touch” (HT201954). According to Apple, jailbreaking introduces security vulnerabilities by “…eliminating security layers designed to protect your personal information and your iOS device.

True. Jailbreaking is a process that is specifically designed to circumvent security layers designed to protect information on iOS devices. In fact, this is exactly why we need a jailbreak for tools such as Elcomsoft iOS Forensic Toolkit to operate. Without a jailbreak, we would not be able to access the file system, extract sandboxed app data or decrypt the keychain (including items secured with the highest protection class). Installing a jailbreak, on the other hand, allows us doing all of that – and more. (more…)