Free threat intelligence feeds worth monitoring in 2025

Compiling a list of free threat intelligence feeds that are actually useful. Here are my top picks:

• AlienVault OTX – community-driven threat data
• Abuse.ch (URLhaus, MalwareBazaar, ThreatFox)
• CISA Known Exploited Vulnerabilities Catalog
• PhishTank – community phishing verification
• Shodan – internet-connected device search

What else should be on this list?

Great list! I’d add:

• GreyNoise – helps distinguish targeted attacks from internet noise
• Censys – internet-wide scanning data
• MISP – open source threat intelligence platform for sharing IOCs
• VirusTotal – free tier is limited but still useful for quick checks

Pro tip: Use MISP to aggregate all these feeds into a single platform that can auto-export to your SIEM.