If all of the tested ports were shown to have stealth status, then for all intents
and purposes your computer doesn't exist to scanners on the Internet!
It means that either your computer is turned off or disconnected from the Net (which
seems unlikely since you must be using it right now!) or an effective stealth firewall is
blocking all unauthorized external contact with your computer. This means that it is completely
opaque to random scans and direct assault. Even if this machine had previously been
scanned and logged by a would-be intruder, a methodical return to this IP address will
lead any attacker to believe that your machine is turned off, disconnected, or no longer
exists. You couldn't ask for anything better.
There's one additional benefit: scanners are actually hurt by probing this machine! You
may have noticed how slowly the probing proceeded. This was caused by your firewall! It
was required, since your firewall is discarding the connection-attempt messages sent to
your ports. A non-firewalled PC responds immediately that a connection is either refused
or accepted, telling a scanner that it's found a live one ... and allowing it to get on
with its scanning. But your firewall is acting like a black hole for TCP/IP packets!
This means that it's necessary for a scanner to sit around and wait for the maximum
round-trip time possible — across the entire Net, into your machine, and back again
— before it can safely conclude that there's no computer at the other end. That's
very cool.
