If you want to know whether an IP is from a VPN, Tor or a compromised server you can do that for free using the Shodan API (https://developer.shodan.io https://

If you want to know whether an IP is from a VPN, Tor or a compromised server you can do that for free using the Shodan API (https://developer.shodan.io https://developer.shodan.io). Disclaimer: I'm the founder of Shodan and identifying the type of connection is something we're often used for.