A PC firewall is a computer application, which controls traffic to and from a computer. Based on one or more security policies, they can allow or deny communications to and from a computer. A personal firewall is different from a conventional firewall because it is mainly designed for end-users. These firewalls are unable to protect an entire network, like conventional firewalls can. It will protect only the computer on which it is installed.
A PC firewall will simply ask whether to allow or disallow a connection to or from the computer. This way, they are able to control the traffic more efficiently and change the security policies according to the user’s preferences. Some personal firewalls also provide a limited intrusion detection system and are able to detect a potential intrusion and block the connection. The firewalls can either block the connection or terminate it, depending on what time the intrusion is detected.
Personal firewall features
Personal firewalls have some very good features that make them effective at stopping intruders from even knowing if your computer is behind an IP address improving your computer security. Here are some common features:
• The user is alerted whenever an application attempts to establish an outgoing connection
• Allow you to manage the basic security rules
• Detect any application that is listening for incoming connections
• Block any unwanted traffic from installed applications
• Provide in-depth data about the application that is trying to establish a connection
• Provide in-depth data about the destination server with which the application is attempting to make a connection. Very useful when it comes to detecting malicious connections
• Hide a computer from port scans by not responding to any illegitimate request. This makes it impossible to see if a computer is really at a specific IP address
• Allow a user to give network access to different applications, while denying access to others
Personal firewall problems
The PC firewall is a computer program and it requires resources to run. This means that if you have a slow computer, installing a firewall will slow it down even more, although it increases its security. Moreover, attackers can also target firewalls themselves. An example would be the Witty worm.
If the system is infected by malware (spyware and adware), these malicious pieces of software can tamper with the firewall and even bypass it. There were also cases in which firewalls were completely shut down, allowing any unauthorized access to the machine.
Due to the large number of alerts, some users can make a habit of clicking “Allow”. Most of these alerts come from applications that are not malicious but when one really is, the user will still click “Allow”. This is a very dangerous practice!
Some firewalls work at the kernel mode level and can cause instability and frequent crashes. If one of these firewalls is compromised, the entire operating system can be rendered unusable! Be very careful what you install! Some firewalls are also known to introduce bugs and security flaws in the system. Any malware can take advantage of these security gaps.
Bottom line
Personal firewalls are very useful! They will protect your computer from any unauthorized access. However, always make sure you install a good tool! Always read reviews on the firewall you choose. Learn from other peoples’ mistakes whenever possible and protect yourself from poorly written software!