Can comparing hashes detect malware in a file or software?

Yes, comparing hashes can help detect malware in a file or software. Here's how it works:

Hashing: A hash is a unique string of characters generated from the contents of a file using a hash function (e.g., MD5, SHA-256). Even a small change in the file's content will result in a completely different hash value.

Comparing Hashes: If a file is known to be malicious (e.g., a virus or trojan), its hash will be available in malware databases. By comparing the hash of a file with those in these databases, you can determine if it is malicious or not.

Use in Malware Detection: Security tools often use this technique to check files against known malware hashes, as it provides a quick and reliable way to detect known threats. If a file’s hash matches one from a malware signature database, it is flagged as potentially harmful.

However, this method can only detect known malware that has already been identified and hashed. It will not detect new, unknown malware or modified versions of existing malware that have changed their hash values.