Technology and tools
What is Hash?
A fixed length value computed from a file's contents. It identifies the exact file and changes completely if one byte changes.
A hash is a fixed-length value computed from a file's contents by an algorithm such as SHA-256, SHA-1 or MD5. The same file always produces the same hash, and changing a single byte produces a completely different one.
That makes hashes precise identifiers for exact files, ideal for searching sandboxes, sharing indicators and confirming that evidence was not altered. It also makes them fragile: an attacker who recompiles or pads a file gets a new hash for free.