Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1 Hash

What is Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1?

The **Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1** hash format emerged as a proprietary extension of Microsoft’s legacy password storage mechanism, primarily used in versions of Office Suite (including Outlook, Word, and Excel) released before 2004. This scheme leverages a hybrid cryptographic pipeline where an MD5-based key derivation function (KDF) preprocesses the plaintext password into a 128-bit intermediate key, which is then fed into a stream cipher mode of RC4 (specifically, RC4 with a fixed initialization vector of `0x0000000000000000000000000000000

Identifying Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1 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 ≤ 2003 (MD5+RC4) collider-mode #1, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1

If you need to recover the plaintext password for a Microsoft Office ≤ 2003 (MD5+RC4) collider-mode #1 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.