AbuseIPDB

Threat Intelligence
Botnet Tracker
A research blog by Marcus Hutchins. Topics include: malware analysis, threat intelligence, and vulnerability research.
CyberCure - Free Cyber Intelligence Feeds
CyberCure.ai provides reliable qualified Cyber Threat Intelligence Feeds for Free and for subscription.
martenson/disposable-email-domains
a list of disposable and temporary email address domains - GitHub - disposable-email-domains/disposable-email-domains: a list of disposable and temporary email address domains
Index of /fwrules
Exploitalert - database of exploits
Exploitalert
GreyNoise Intelligence
GreyNoise captures data on IPs that scan the internet and saturate security tools with internet noise, so SOC teams can focus on threats that matter and ignore those that don’t.
MDL
Maltiverse
Ransomware Tracker
ThreatMiner.org
ThreatMiner is a threat intelligence portal that provides information on indicators of compromise (IOC) such as domains, IP address, malware samples (MD5, SHA1 and SHA256), SSL certificates, WHOIS information and malicious URLs such as phishing and malware links.
VirusShare.com
VirusTotal