Scan IP Addresses, Files, Domains and more
I would be surprised if you didn't know this site. One of the first places I go to when investigating a IP Addresses, URLs and Files.
https://www.virustotal.com
Sandbox
https://www.hybrid-analysis.com
https://app.any.run/
Data mining for Threat Intelligence.
https://www.threatminer.org/index.php
A search engine for threats.
https://www.threatcrowd.org/