A firewall protects your computer from many things but above all from hackers and malware. Hackers are people who are attempting to access your PC remotely, without your knowledge and consent. Why do they do it? Well, not only because they earn money from doing this but also because they want to steal private information, for fun or just to cause mayhem.
Hackers are known for sending malware to your PC. Malware includes pests such as viruses, Trojan horses, spyware, rootkits, etc. A firewall does not clean malware (an antimalware program does) but it can stop it from entering your PC based on rules you set.
Malware often comes integrated with an e-mail attachment and with catchy names like ‘free_games_download.exe’. When the attachment is opened, you install the malware on your PC. Some download websites have infected games, screensavers, utility programs, etc to download. Their purpose is to bring malware to your PC with means of the program you may download.
The risks of getting malware from within an internal network can not be neglected. Employees and other members within one particular network may have one or more hackers sitting among them. We would not want our files stolen or privacy exposed to anyone – whether from within or outside the network.
A firewall comes in use here as well, keeping an eye on all members of the internal network and preventing them from breaking into any PC with prying intentions. Moreover, a firewall would make sure users in the internal network use authorized resources that are located on the outside network.
Malware can bring havoc to the PC. Hackers can spy on you very easily with a malware-infected PC. A hacker can steal, delete, and change information on your PC. If you use Microsoft Outlook or another similar program, malware can read your entire address book and send itself to all your contacts in hope that others will open and run it, too.