rDNS: ec2-3-212-227-51.compute-1.amazonaws.com
#Id Port Banner Type Ttl Service
4,419,910,237 22
SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.2
response 51 ssh
4,419,909,725 22 syn-ack 51
113,128,939 22
SSH-2.0-OpenSSH_8.2p1 Ubuntu-4ubuntu0.2
response 47 ssh

This project goes around the Internet and finds services to index them.