Sucuri Alert, Post Update, Ip Address/Reverse IP Address

I keep on getting a lot of Sucuri Alert, Post Update emails for all of my sites. The message is always:

Message: Nf_sub status has been changed; details: ID: 2288,Old status: new,New status: publish,Title:

And there will be an IP Address and a Reverse IP.

I am not certain what these messages mean. They look incredibly suspicious since I haven’t edited my site or made any updated to it – could someone shed some light on what these mean?