Let's say you have some open ports like 139 or 427 or someting in that range. How does one a hacker for example access it and get in your computer? Can someone direct me to a link for some info on that. I know that some hackers have programs that can attack open ports but and I have a port scanner so I know what ports I have open on my computer but how can I test it for security?

Try thepublicworks, wilders.org gibson reasearch and pc flank for information and port scans. Take care!

Here's the deal...you should definately do some research regarding service to port mappings. i.e 139 - netbios; 25 - smtp... I think that IANA has a current listing of the reserved TCP/UDP ports. When a hacker is looking at open ports the first thing he/she will usually do is test to see what service is running on that port. It gets a little tricky once you are above the 1023 port range. These ports usually map back to proprietary (sp?) applications. Once you figure out what app/service is bound to the open port(s) you just need to fire up an app of your own that will connect to that service.