file-by-hash
VirusShare
An invite-only repository of tens of millions of malware samples, with hash lookup and sample download for members. Getting in means emailing the operator for an account; the API likewise needs the member key. Researchers turn to it when they need the actual sample behind a known hash and the open repositories do not have it.
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Search this archive
No programmatic check — opens the archive’s own search.
Why it’s useful & how it works
INVITE-ONLY account (email operator) → key; CF/bot challenges on some paths. High barrier, niche. Link-only unless invited.
What’s inside
Tens of millions of samples.
API access
https://virusshare.com/apiv2/file?apikey= <KEY>&hash=<h>
An API key is required — usually free; see the endpoints above for where to get one.
Access
May require solving a captcha before it responds.