subdomainfinder c99 nl

Google Search Console complains about Redirect errors from...
support.google.com
In https://search.google.com/search-console/, under Index → Coverage, we see 404 Redirect Errors for a Marketo subdomain, `go2.$our_domain`. When I click the magnifying glass icon to view details, I see this comes from a scraping tool, https://subdomainfinder.c99.nl/.

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