Bulk Domain/IP lookup - https://www.infobyip.com/ipbulklookup.php
Batch Domain/IP lookup - https://cybergordon.com/
IP/Domain owner - https://app.netlas.io/host/
IP/Domain owner - https://centralops.net/co/
WHOIS - https://whois.domaintools.com/
WHOIS - https://who.is/
Domain/IP lookup - https://search.dnslytics.com/
Domain/IP lookup - https://www.urlvoid.com/
Domain/IP lookup - https://labs.inquest.net/repdb
Scam database lookup - https://www.scamadviser.com/
Bulk IOC lookup/indexing - https://otx.alienvault.com/pulse/create
Single IOC lookup - https://www.virustotal.com/gui/home/search
Single IOC lookup - https://pulsedive.com/
IP reputation lookup - https://www.ipvoid.com/
IP or /24 subnet lookup - https://www.abuseipdb.com/
Sandbox submissions - https://app.any.run/
Blacklist checks - https://mxtoolbox.com/blacklists.aspx
Blacklist checks - https://check.spamhaus.org/
Botnet C2 checks- https://feodotracker.abuse.ch/browse/
Subdomains/DNS lookup - https://dnsdumpster.com/
Proxy check - https://www.ipqualityscore.com/
IP check - https://www.ipvoid.com/
URL check - https://www.urlvoid.com/
SSL check - https://sslbl.abuse.ch/ssl-certificates/
CDN check - https://www.cdnplanet.com/
URL check - https://urlhaus.abuse.ch/browse/ [query syntax required e.g. url: or domain:]
Single IOC lookup - https://threatfox.abuse.ch/browse/ [query syntax required e.g. ioc:]
IP lookup - https://www.greynoise.io/ [query syntax required e.g. ip:]
Sandbox submissions - https://urlscan.io/search [query syntax required e.g. ip: or domain:]
Sandbox submissions - https://tria.ge/s [query syntax required e.g. ip: or domain:]
Threat Intel Platform - https://opentip.kaspersky.com/
Threat Intel Platform - https://www.threatminer.org/index.php
Threat Intel Platform - https://pulsedive.com/analyze/
Threat Intel Platform - https://metadefender.opswat.com/
Firewall Lookup - https://urlfiltering.paloaltonetworks.com/query/