NetBrute Scanner
A network is only as secure as its weakest link, and in many cases that's shared folders or mistakenly open ports. Trying to find all the shared folders and open ports on a network -- even a small one -- can be a difficult, time-consuming task.
This free suite of three simple security tools will put your network through a basic security check, looking for shared resources and open ports. As a bonus, you can also use it to test the security of any webservers on your network.
You can check for shared folders and resources, as well as open ports, on any individual PC on the network by using its network name or IP address. You can also scan an entire range of IP addresses, although I found that feature to be somewhat flaky; it didn't find all the PCs on my network. However, scanning individual PCs worked fine.
The program lists all shared resources and, better yet, lets you connect to those resources and browse them from the program as well. The program also scans the PCs on the network for open TCP ports, so you'll be able to find out what webservers, FTP servers, Telnet resources and the like are installed. More important, it will show you where your port vulnerabilities are.
The final utility in the suite checks the webservers on your network and sees whether it can break into them using a "dictionary attack" by trying combinations of usernames and passwords to gain access to the webmaster's account.
There are a variety of technical limitations to this program; before using it, it's a good idea to check out its details. Still, it's free, it's simple, and it's fast, and because of that, more than worth a try.
Technitium MAC Address Changer
There are plenty of ways to protect your home wireless network against intruders. One is to block anyone from connecting to your network except those who have network cards with specific MAC addresses. It's easy enough to set your router to block out intruders. But how do you know if it really works?
By checking it yourself. One of the best ways to do it is to spoof a MAC address, by giving one of your existing network cards a new address. You can do it with this software that lets you change your MAC address with a few simple clicks. Run the program, highlight the network card that you want to give a spoofed MAC address, click Random MAC Address, and then click the Change Now! button. That's all it takes. To restore to your original MAC address, highlight it and click Original MAC.
This program has other uses as well. It's a great way to show all the details about your network cards, including the manufacturer name; MAC address; and IP, Gateway and DNS information associated with each of your network cards. It includes other useful utilities, such as releasing and renewing an IP address for a card, which can help fix broken network connections.
RogueScanner
Here's an even better way to find out whether your network has any intruders on it: Run this program. Before you run it, put together a list of every PC and device on your network. Once you have that in hand, run RogueScanner. It lists every device on your network, including routers, printers, PCs and others. For each device, it lists the IP and MAC addresses. In addition, it peers deeper and tries to find other information, such as whether the device is a workstation, printer, server, router or PC, as well as the manufacturer and model number.
Compare what the program finds with the list of devices that you know are safe and secure. If you find a device on the network that's not on the list you drew up, you've got an intruder.