OSX v10.8 Hash

What is OSX v10.8?

The **OS X v10.8 (Mountain Lion) password hash format** is a proprietary cryptographic scheme introduced by Apple in 2012 as part of its transition from the older Unix-style MD5-based password storage to a more secure alternative. Structurally, it combines a **PBKDF2-HMAC-SHA1** key derivation function with a **salted iteration count**, where the salt is derived from the user’s password and a system-wide secret key (the "keychain master seed"). The format stores the hash as a binary blob containing the salted PBKDF2 output (typically 32 bytes for SHA1), an iteration count (often 60,000 by default), and a version identifier. This design was intended to mitigate brute-force attacks by enforcing computational overhead via iterative hashing, though it retained a reliance on SHA1—a now-obsolete cryptographic primitive—while introducing a per-user salt to reduce rainbow table attacks. Its primary use-case was securing local user authentication in macOS, particularly for the login window and keychain access, though it was later deprecated in favor of more modern formats like **Apple’s salted SHA-512** in macOS 10.10 (Yosemite).

The **vulnerabilities of OS X v10.8’s hash format stem from its reliance on SHA1, weak iteration counts, and GPU-accelerated cracking**. SHA1’s collision resistance has been shattered (e.g., via FIPA attacks), and its preimage resistance is now considered insufficient for password storage. While PBKDF2 with a salt mitigates some rainbow table risks, the default iteration count (60,000) was easily optimized using GPU-based cracking tools like **Hashcat** or **John the Ripper**, which leverage CUDA/OpenCL to evaluate millions of hashes per second. Additionally, the salt derivation process—tied to the user’s password—can be bypassed via **salting attacks** if the master seed is leaked, and the absence of a per-hash salt in early implementations (pre-10.8.3) further reduced security. Finally, the format’s reliance on SHA1’s 160-bit output space makes it susceptible to brute-force attacks when combined with weak passwords or leaked password databases, as demonstrated by real-world breaches where OS X v10.8 hashes were cracked in hours using distributed GPU clusters.

Identifying OSX v10.8 Hashes

Identifying a hash blindly is often difficult because multiple algorithms can output strings of the exact same length. For example, a standard 32-character hexadecimal string could be MD5, NTLM, MD4, or LM. To definitively identify OSX v10.8, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack OSX v10.8

If you need to recover the plaintext password for a OSX v10.8 hash during a penetration test or forensics investigation, you must supply the correct module ID to your cracking software. Use the exact commands provided at the top of this page to target the hash successfully.