Deleted subdomain still visible through Subdomain Finder Tools

Question

I have a couple of subdomains that have been deleted(more than a year ago). I was curious if the deleted domain can be tracked.

So, I used a subdomain finder tool from https://subdomainfinder.c99.nl and https://ipsaya.com/en/find-subdomains. It turns out that all of my deleted subdomains are still visible. I've checked my domain record, and the deleted subdomains are no longer there. I tried to delete all files related to the deleted subdomains, and it is still visible through that tool.

Is there a way to remove all of that permanently?

Answer 1

Subdomainfinder and similar systems work as follows:

They try to crawl as many sites as they can with their own crawling bots. While crawling these sites, they try to find subdomains by trial and error and from DNS records. They save the subdomains they find in their databases.

After saving them in the database, they show the subdomains of the sites they scan through their own websites. If you had deleted your subdomain name before Subdomainfinder and similar systems crawled it, your subdomain name would not be found in their database and naturally your subdomain name would not appear in their system.

What do you need to do?

Unfortunately, they keep subdomains in their databases because they have already crawled them, and even if you delete the subdomain, it will still show up because they have already registered it in their database as a subdomain.

If this is a critical issue, you can contact them via email and ask them to delete the subdomains from their database.