File reputation
Check a file hash
Paste a file's hash and see how many security engines flag it on VirusTotal. You send only the fingerprint - never the file itself.
Frequently asked questions
What is a file hash and how do I get one?
A hash (MD5, SHA-1, or SHA-256) is a short fingerprint of a file's exact contents - change one byte and the hash changes completely. On Windows: certutil -hashfile yourfile.exe SHA256. On macOS/Linux: shasum -a 256 yourfile. Paste the result here.
Do I upload my file to Cactus?
No. You only ever send the hash - never the file itself. We look up an existing VirusTotal report for that fingerprint; nothing is uploaded, scanned, or stored.
What does "unknown to VirusTotal" mean?
It means no one has ever submitted that exact file to VirusTotal. That's common for brand-new or rare files and is NOT a clean bill of health - a fresh piece of malware is unknown until someone reports it. Stay cautious.