IIS Log question

Hi,

I'm using IIS 8.5 on server 2012.

I just saw in my website log the following raw:

2015-05-24 07:41:43 "My.Server.Ip" GET / - 80 - 61.240.144.65 masscan/1.0+(https://github.com/robertdavidgraham/masscan) - 200 0 0 873

My website in not on production, i don't even have a domain yet.

This ip: 61.240.144.65 is out of my country, its from china, i checked the link "https://github.com/robertdavidgraham/masscan" and its

some kind of an internet segment port scanner, Can someone give me some move details ?

Is someone trying to hack to my server ? if so, what kind of a hack is that and how can i prevent it ?

Thank you very much