ExoneraTor

Checks whether an IP address was running as a Tor relay on a given date, which tells you if traffic from it could have come from Tor users.

https://metrics.torproject.org/exonerator.html

Takes

Community database of reported malicious IPs. Shows abuse reports, a confidence score, the ISP and the usage type.

TakesIP addressDomain

Community threat-intelligence exchange. Look up an IP, domain or file hash to see the reports and campaigns it appears in.

TakesIP addressDomainFile hash

Official registry lookup for IP ranges and networks in North America: who holds an address block and their contacts.

TakesIP addressCompany

Checks an IP address or domain against 100+ email spam blocklists at once.

TakesIP addressDomain

Community blocklist of IPs caught attacking servers (SSH, mail, web logins). Search an IP to see what it was reported for.

TakesIP address

Database of names, emails and IPs used by spam bots on forms and forums. Check whether an address is a known bot.

TakesUsernameEmail addressIP address