Here’s how to monitor your network connections in Windows XP/Vista/7/2003 Server/2008 Server with TCPEye:
1. Visit this link and download the TCPEye Network Tool.
2. Install TCPEye like any other windows application and double click the TCPEye icon to launch the application after the installation is finished.
3. The application will show you a list of currently open TCP/IP and UDP ports on your system along with the process that opened the port, local and remote IP address, state of the connection, protocol used, country of the remote IP address, process path, product/company name, and file description/version.
4. Right clicking a process gives you many options including options to close the connection, end the process, check the process with anti-virus(VirusTotal) etc.
If you find a process to be suspicious, Google the process name to find more information about the process and then take appropriate action as required.