Friday, August 24, 2007

Securing your home computer in a large apartment complex

Working in the computer security field I'm always concerned about privacy and security. Living in a large apartment complex there is an increased risk of having your home network hacked when you use wifi. Even if you weren't worried about security if someone was to "borrow" your wifi you will now be sharing your bandwidth with other people which will degrade your own performance.
Well here are some very simple steps to secure your computer/network. I will start from the basic setting changes and gradually step up the security.

Everyone should have a firewall. All routers come with a hardware solution for firewall blocking/filtering, but I think you should also have a software based solution on your computer as well. With XP SP2 microsoft introduced a firewall. It's very basic, but its better than nothing. Ideally you should have a firewall from a software provider. You don't necessarily need to buy the software as long as you use it for personal/home use. I really liked Sygate Personal Firewall but they've now been taken over by symantec and I'm not a big fan of them. Another product I liked is ZoneAlarm Free and they keep improving their product.

Now I'm on vista and I thought the built in firewall would be good. It's better than the version on XP SP2, but one thing that it doesn't do is outbound filtering. It has inbound filtering so if someone from the outside tries to get in you will get a notification. Now lets do the reverse scenario. If you had spyware on your computer or a keylogger then that program can connect to the internet and pass your information on. Now if you're on vista 64bit version there aren't many options for firewall solutions. The only ones I know of are AVG and Comodo (but it's only in beta version). Here is my philosophy...don't install programs unless you have to. For example, do you really need to have a 3rd party DVD media player if Windows Media Player can do it?

Well I have the perfect program for you. It's called Vista Firewall Control by Sphinx Software. It's a great program because it works with the firewall that comes with Vista, but it actually will prompt you when an application tries to connect to the internet. If you were going to use the vista built in firewall you would need to setup rules for everything you want to connect to the internet in advance. With Vista Firewall Control you don't need to setup rules in advance. As applications attempt to connect to the internet you will get a notification and at that point you can either block it or allow it. I've been using it for a few weeks and so far no problems. It has a small footprint (not a large application and doesn't use a lot of memory). One issue I do have with the free version is it's sometimes hard to identify the application that is being blocked. For example you will get a popup that the BONJOUR service is being blocked. What the hell is that? Immediately I thought it was some keylogger, spyware or trojan. I then googled it and found out it's an Apple program. Now how would you ever know this was an apple program? The firewall will pop=up the filename/location and the application description (as long as the
information can be gathered from the application). In some cases you will immediately recognize the applications and in other cases you will have to google it. To download this from Sphinx you can go to: http://sphinx-soft.com/Vista

Next, when you use your wifi router you should always change the broadcast ID (known as SSID) from the default settings. How many times have you scanned for hotspots and you see netgear or linksys? Decrease the potential of someone automatically connecting to these known default SSIDs by changing them.

You should disable the broadcast of your SSID. Disabling your broadcast would prevent others from seeing the name of your router. Without a name it's more difficult for someone to connect to your router unless they had a "sniffer". How many times have you scanned for wireless and you see a hotspot called "unknown"? This is what happens when you disable your SSID

If you need more security then encrypt your wifi. In the good ole days you had WEP and all routers still support this technology. If you have a newer router I would highly recommend WPA2. The encryption is substantially more secure and you can set it to change the group key at specified intervals. Now if you have an older router than using WEP is better than not using anything at all.

Lastly, use MAC filtering. While you can "spoof" a MAC address the general public will not know how to do this. A MAC address is a unique identifier for a computer. By setting up MAC filtering you're telling your router to only allow a connection from a computer that has a MAC address you entered into the router. If your MAC address isn't in the router...then you're not getting in.