Rule : Default Windows File Sharing

I was checking the log of my antivirus, I found in th log:
4/3/2007 10:10:43 PM,"Rule ""Default Windows File Sharing"" permitted (###.##.###.133,netbios-ssn(139)).","Rule ""Default Windows File Sharing"" permitted (###.##.###.133,netbios-ssn(139)).  Inbound TCP connection.   Local address,service is (MYPCNAME(###.##.###.186),netbios-ssn(139)).  Remote address,service is (###.##.###.133,3426).  Process name is ""System""."

now I live in a building where there are 200 pcs on a Lan all start with ###.##.###.XXXX , where XXXX is a fixed number of each user. I dont know the address ###.##.###.133 mine is ###.##.###.186, does it mean someone is hacking mine, as I find the message several times!!, what is this "rule" and how to secure my pc better.
TheSilverBulletAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

CoccoBillCommented:
Are all the machines in the network are in the same segment? It looks like someone is trying to access your file shares. I wouldn't call it hacking, just that someone is using a service that your computer has open. You might want to stop sharing your folders if you have no need to do so, or at least protect the shares from outsiders with ACLs.

http://support.microsoft.com/kb/304040
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
OS Security

From novice to tech pro — start learning today.