Let’s talk about your home network. In the old days we used a 300 baud modem to connect to a bulletin board somewhere. Modems got faster. The Internet brought many more interesting destinations. And today we have wideband Internet access constantly connected to your home. And your home network has two or three PC’s a printer or two and a WIFI hotspot. All of these are potential security failures that can cost you money, reputation and even your name.
We’ll start with your Internet access device. It connects your home network to the cable or DSL(phone). It should have a builtin firewall and unless you have a specific application that requires Microsoft network services you want to turn off everything except TCP Version 4 and TCP Version 6. Allowing printer and file sharing over the Internet is about the same as leaving your front door unlocked. You’re just asking for trouble. Most people only need port 80 for your web browser, port 53 for DNS and 110/143 for email, nothing else. There is one other thing you could do, but you won’t. And that is to disconnect or turn off your Internet connection when you’re not using it. The bad guys can’t break in if you are not connected!
You probably also have wifi, it’s all the rage these days. Please make sure you have WEP enabled. At least that will keep honest people out. Most people set up their wifi to allow any service to any computer on their home network. After all wifi is a matter of convenience, you don’t have to plug in your PC. You can take your laptop out on the patio and surf the Internet or copy files from your desktop PC while enjoying breakfast. Look Ma, no wires! Unfortunately that also means that the bad guys can park out front and break into your system. If you have file sharing and such enabled over a wifi at least have it password protected. This is kind of like leaving your wallet on the front lawn. And with the latest antennas and wifi cards they don’t even have to be close to your house. They can break in from blocks away.
You can think of all of that stuff as the highway bad guys travel to reach their destination … your PC. This is what they are after. They want to install keystroke logging programs to capture your bank account login and password. They want to install botnet software so they can use your computer to attack others. They want to install SPAM software to send email in your name. They are inventing more diabolical schemes every day.
How do you protect yourself? First download and learn how to use these programs; Nessus, Nmap and Wireshark. Whenever you suspect your computer is acting strange, running slow, locking up or changeing the way it works you can run these programs and find out if your gremlin is a thief. Nessus and Nmap scan computers and networks to see what ports are open. If you find ports you don’t need close them. Wireshark monitors network traffic. It will show you what information is being received and sent thru the network. I also run a CRC check on all of the programs and files on my computers. If something is changed I want to know about it.
Finally you should have virus software running, especially if you are using a Microsoft OS. Newer windows versions have Defender built in and you can get McAfee, Norton and others from the Internet. Use it! With a little luck the bad guys will go bother someone else, someone more inviting.