How to Find Out If You Are Secretly Connected to the Internet


Want to know which programs on your PC are connecting to the Internet? Ever have the disconcerting experience of your PC suddenly engaging in mysterious Internet activity? Find out what is going on with a free utility from NirSoft called CurrPorts

Long-time Gizmo readers may recognize that this program has been around for quite a while. In fact, Gizmo’s newsletter recommended it back in 2008. But the developer keeps improving and revising the program so it is quite up to date. Many PC users are unaware of it and it is worth revisiting this little tried and true utility.

CurrPortsAs explained in the article at this link, being on the Internet actually involves multiple connections using what are known as ports. CurrPorts will tell you what ports are open and what programs or process opened those ports. It also provides a wealth of information about the processes, including the full path of the process, the product name, file description, and much more. It will tell you the IP of the Internet site that is being connected to by a particular process. Any suspicious ports are flagged in pink. An option to close any suspect TCP connections is provided in the File menu along with another option to kill the process that opened it. An abbreviated example of the CurrPorts interface can be seen by clicking the first thumbnail. There are actually 24 columns of information in a full view. The Interface can be configured to show whichever ones you are interested in. A full list of the various kinds of information in the CurrPorts display can be seen by clicking the second thumbnail. CurrPorts views

The program is now in version 2.09. It requires no installation and is portable. It works in all current versions of Windows, including 8.1. There are both 32- and 64-bit versions. More details are at the developer’s page. The download links are near the bottom of the page, just above the foreign language versions.

And there you have it – now you can find out who is trying to “phone home” and where "home" is.

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This tips section is maintained by Vic Laurie. Vic runs several websites with Windows how-to's, guides, and tutorials, including a site for learning about Windows and the Internet and another with Windows 7 tips.

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The "netstat" command-line tool comes standard with Windows and does much the same job – although it lacks the nice GUI, of course.

Kdyer recommended Sysinternal's TCPView. that's good too, but does not show as much detail as CurrPorts. for example the executable path on your pc is useful, it's not always clear just from the .exe name itself so I prefer CurrPorts. however, TCPView just showed me a device driver that was turning red off and on. it was an extra video card that is not being used. So it helped me disable that.

Thanks , Vic, for reminding me about this neat little gem.
I use it and kyder's recommended TCPView which, as with all Sysinternals, NirSoft makes easy to include in its *NirLauncher* packages.

Thank you for revisiting CurrPorts otherwise I wouldn't have known about it :D. It's tiny (211 KB unzipped) and portable - what more can I ask for? I love free and portable! :)