DataHub v1 is the original DataHub catalog of 11,000+ open datasets, now migrated to PortalJS Arc.
Dataset

Internet Storm Center

The Internet Storm Center has a large number of security related tools. For example, it includes a service which checks file MD5 hashes against a database of of tens millions of confirmed malware.

Download & API
Hash Databasefile
Hash Database
Download
base64 Decoderfile
base64 Decoder
Download
Hash Calculatorfile
Hash Calculator
Download
EXIF Readerfile
EXIF Reader
Download
IPv4/IPv6 Conversion & Analysisfile
IPv4/IPv6 Conversion & Analysis
Download
Reverse Hash Lookupfile
Reverse Hash Lookup
Download
Whitelist Hash Searchfile
Whitelist Hash Search
Download
Suspicious Domains Searchfile
http://isc.sans.edu/tools/suspicious_domains.html
Download
404 Projectfile
404 Project
Download
whereis Lookupfile
whereis Lookup
Download
Sources & license