As Macintosh computers continue to gain popularity, especially with the introduction of the Silicon Macs, digital forensic examiners must stay up-to-date with the latest tools and techniques for conducting examinations on these systems. While some of the same principles and procedures used in traditional Windows computer forensics methodologies may apply to Macintosh systems, extracting and examining data from a Mac pose unique challenges requiring specialized knowledge and tools.
One of the first challenges in Macintosh forensics is dealing with the proprietary Apple file systems. Modern Macs use the Apple File System (APFS), which with its Secure Enclave and virtualized volumes, offers its own challenges in imaging and analyzing data. You may also run into Mac OS Extended, aka the Hierarchical File System Plus (HFS+), on Intel Macs or macOS formatted external media.
APFS and HFS+ are very different from the NTFS and FAT file systems. This means that forensic tools designed for Windows will not be able to properly handle Mac file systems the same way a Mac forensic system can. Even those Windows-based tools that say they can parse Mac data will miss or not fully parse data because they have to rely on reverse engineering of the Mac file system and operating system.
Another challenge in Macintosh forensics is dealing with Apple’s increasing use of encryption. FileVault 2, APFS Encrypted, Secure Enclave, T2, APFS individual file encryption, where will it end? Well, it isn’t. These security features make it increasingly difficult for examiners to access data on the hard drive without the user’s password. Let’s face it; in many cases, unless you have the login password, your Mac is a lovely plant stand or a doorstop. In some circumstances, it may be possible to use a brute-force attack to crack the password, but that poses its own challenges, the least being the process being very time intensive (think years and years).
In addition to file systems and encryption, Macintosh forensics also involves the analysis of artifacts unique to Apple computers. For example, macOS stores a file’s extended metadata separately from the file data; this includes the extended attribute date/timestamps that macOS uses extensively. It also has data in hidden or obscure locations, such as the Spotlight index, Document Revisions, the user plist, and APFS local snapshots. These artifacts can be valuable sources of evidence for digital forensic investigations, but you need to know where to look. Furthermore, Apple products often use proprietary files and metadata formats, requiring specialized knowledge and tools to parse them.
Macintosh forensics is a complex and evolving field that requires specialized knowledge and methodologies. As more users and organizations adopt Macintosh computers, it becomes increasingly crucial for examiners to understand the unique challenges and techniques involved in analyzing data on these systems. By staying up-to-date with the latest developments in Macintosh forensics, digital forensic investigators can provide more effective and efficient findings for their investigators and legal counsel.
SUMURI’s Mac Forensics Survival Courses provide hands-on training and practical experience in conducting Mac Forensics using a Mac and free or low-cost tools. The courses provide a comprehensive understanding of macOS’s file systems, artifacts, and technologies that will give the student the knowledge and training to conduct Mac Forensic examinations confidently.