Firewall Software and Internet Security

What are the threats?

There are over a billion people using Internet on daily basis. We are doing this from home and from our workplace; from our personal computers, laptops, mobile phones and TV sets; to search for information, to communicate with other people and to buy and sell goods and products. There is more - just think about the personal information that is stored on your computer - your e-mail messages, your personal photos and videos, chat logs, browser history, history of the all recent documents that you have read or created.

What happens if all this information falls in the wrong hands? Disaster. But how this could happen? The information is on your computer and you never send your personal information over the Internet. The dark truth is that there are countless ways for people with malicious intentions to invade your privacy. All they have to do is to place a small program (malware, trojan or virus) on your computer. The malware than will search for valuable information and will send it to its creators. After that they will most probably use your computer as a tool to infect other computers, to attack Internet sites for profit and to send spam messages.

In order to understand the other precautions you can take, lets see which are the most common ways to steal information and get control over your computer:

* Infecting of the computer through download of malicious program. One of the great advantages of the computers is the vast variety of programs that can be downloaded and installed. Most of these programs are genuine and can be trusted but more and more viruses, trojans and rootkits disguise themselves as useful programs. One special case are the modified versions of respected programs that are infected with malware and adware or the so called cracks for popular programs.

* Infecting through files that are not looking like programs at first glance. For example you may download a song or a video file from the Internet and it may contain an executable file. Another common example are the screensavers, which are programs and are just as dangerous as any other program.

* Using security "holes" in the operating system or popular applications. The so called exploits use the security problems or "holes" that are unintentionally left open in every major operating system and many popular applications. While most software companies are releasing security updates relatively quickly, most users never upgrade their software or it is too late - they are already infected and closing of the security "hole" does not remove the malware that is already on your computer.

How the firewall protects you?

So, how exactly the firewall protects your computer and the important private information on it? To answer this question, we will need some background information about how the Internet works. Although this is very big topic, we only need a simplified explanation. If you want a better understanding of all the inner workings, you can refer to Wikipedia or other online in-depth publications.

Lets see what happens when you go to the web site of CNN (www.cnn.com). Because it is not very convenient to remember such numerical addresses, there is another protocol - DNS, which is used to convert the name www.cnn.com to the IP address of the same computer. To do so, your computer sends a DNS request packet to another computer (called DNS server) and asks it for the IP address of www.cnn.com. The DNS server sends a DNS response packet with the requested information and our computer is ready to send another request packet to the computer of CNN and then waits for its response, which will contain the requested web page.

As you can see, in vast majority of cases, your computer acts like a client - it sends request packets to other computers (called servers) and waits for their response. Please note that in this case your computer initiates the connection and the connection is outgoing. This leads us to the simplest type of firewall - one that blocks incoming connections and allows all outgoing connections from your PC. Examples of such firewalls are the built-in firewalls in Windows XP and Vista. While this type of firewall provides some protection, it leaves a lot to be desired because it makes one dangerous assumption - that all programs or your computer are not malicious and can be trusted to create outgoing network connections as they want.

More advanced firewalls, like Mil Firewall, are inspecting both incoming and outgoing connections. Furthermore, they remember which program is initiating each connection and then use this information to do better job without getting in the way (also called stateful inspection). However, there is another drawback - the more advanced firewalls tend to use a lot of CPU and network resources and slow down your computer.

With the special firewall protection scheme, used in Mil Firewall, you do not have to sacrifice the speed of your computer in order to block hacker attacks and malware. Mil Firewall is the fastest firewall software and it is very flexible and powerful.