HELP! Rule " Default Block Microsoft Windows 2000 SMB" blocked

Hi all i was just wondering what this entry in my NIS 2011 history means and if its anything to worry about

 

 

Rule " Default Block Microsoft Windows 2000 SMB" blocked (58.106.27.207, Port (445) ). Inbound TCP connection.

Local address, service is ( MY-PC (58.106.234.***), port (445) ).
Remote address, service is (58.106.27.207, Port (12933) ).
Process name is "System".

 

help would be much appreciated :)