Could anyone help me out by letting me know what program is used for scanning .onion sites?
Thanks in advance.
What do you mean by scanning? Are you referring to normal scanning of an IP from a website? You can’t get real IP from .onion websites. If you are just talking about scanning .onion to see whether they are up or not then you can use Onionscan tool.
Yes scanning as in to see what ports are open to launch an attack against the .onion site or patch up before being attacked.
You can use OnionScan for scanning your onion website for any security issues. You can also use something like this: https://blog.hyperiongray.com/port-scanning-a-onion/