Been using Gibsons ShieldsUp and PC Flank http://www.pcflank.com/about.htm for as long as I have known of them which is like the previous millennium. I wont touch any other on-line "test your PC for cleanliness" websites. Am sure one or the other uses it to collect information and place something stealthily. A couple of ports I'm sending to a ghost on an IP that is outside of all the software firewall permitted ranges.

PC Flank result just now:


Packet' type Status
TCP "ping" stealthed
TCP NULL stealthed
TCP FIN stealthed
TCP XMAS stealthed
UDP stealthed

Here's a 'popular' port scan by same:

Port: Status Service Description
21 stealthed FTP File Transfer Protocol is used to transfer files between computers
23 stealthed TELNET Telnet is used to remotely create a shell (dos prompt)
80 stealthed HTTP HTTP web services publish web pages
135 stealthed RPC Remote Procedure Call (RPC) is used in client/server applications based on MS Windows operating systems
137 stealthed NETBIOS Name Service NetBios is used to share files through your Network Neighborhood
138 stealthed NETBIOS Datagram Service NetBios is used to share files through your Network Neighborhood
139 stealthed NETBIOS Session Service NetBios is used to share files through your Network Neighborhood
1080 stealthed SOCKS PROXY Socks Proxy is an internet proxy service
1243 stealthed SubSeven SubSeven is one of the most widespread trojans
3128 stealthed Masters Paradise and RingZero Trojan horses
12345 stealthed NetBus NetBus is one of the most widespread trojans
12348 stealthed BioNet BioNet is one of the most widespread trojan
27374 stealthed SubSeven SubSeven is one of the most widespread trojans
31337 stealthed Back Orifice Back Orifice is one of the most widespread trojans