Microsoft Office 2007 Hash

What is Microsoft Office 2007?

The Microsoft Office 2007 hash format, formally known as **Microsoft Office Document Verification (MSODV)**, is a proprietary cryptographic hash scheme introduced to secure digital signatures and document integrity checks within Office 2007 XML-based file formats (e.g., `.docx`, `.xlsx`). Derived from a modified **SHA-1** (Secure Hash Algorithm 1) with a custom prefix-suffix structure, the format embeds the hash in the XML-based Office Open XML (OOXML) container via the `` element. The primary use-case was to verify document authenticity and prevent tampering by generating a hash of the entire file’s contents (excluding the signature block itself) and storing it alongside an RSA-encrypted digital signature. Unlike traditional hash formats, MSODV does not incorporate a salt or iterative hashing, instead relying on a fixed-length 160-bit (SHA-1-derived) output with a proprietary XML wrapper for metadata. This design prioritized compatibility with legacy Office systems while maintaining a lightweight verification mechanism, though it lacked formal cryptographic standardization.

The MSODV format is vulnerable to cracking due to several inherent weaknesses. First, its reliance on **SHA-1** renders it susceptible to collision attacks, as SHA-1’s pre-image and second-pre-image resistance have been compromised (e.g., via FIPA and SHA-1 collision attacks), enabling adversaries to forge documents with identical hashes. Second, the **absence of salting** or iterative hashing (e.g., PBKDF2) makes brute-force or rainbow table attacks feasible for weak passwords or predictable inputs, though MSODV’s primary purpose was not password storage. Third, the **XML-based structure** introduces parsing vulnerabilities, as malformed XML could bypass validation checks or trigger buffer overflows in older Office parsers. Finally, the **lack of key stretching** and reliance on RSA signatures (without proper key management) exposes the system to private-key compromise if signatures are forged or leaked. Additionally, GPU/CPU optimizations for SHA-1 (e.g., via OpenCL or CUDA) could accelerate brute-force attacks on derived keys if misused, though MSODV’s core vulnerability stems from SHA-1’s deprecated security guarantees rather than computational efficiency.

Identifying Microsoft Office 2007 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 Microsoft Office 2007, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack Microsoft Office 2007

If you need to recover the plaintext password for a Microsoft Office 2007 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.