There's a new search called SHODAN, which can look for servers, routers and printers using your search query, and get their response banners.
This is what you can search for:
- country:2-letter country code
- hostname:full or partial host name
- net:IP range using CIDR notation (ex: 184.108.40.206/24 )
- port:21, 22, 23 or 80
As you can see, anyone can easily find vulnerable hosts just by looking through all the banner responses which the searched sites output. This is really dangerous as many skiddies would just scan hosts anonymously day and night looking for a particular version of apache/ftpd/ssh whatever to exploit.
So what do you think?