The computer viruses are made to make an app or a function not to work properly. And nowadays some idiots are making benefits out of it. Like black / red hat hackers. They analyze the user they want to attack for some days. And then they make a virus and somehow insert the virus to that person's PC / Laptop. It is a family of malware which tries to infect the other programs which are installed on your system. They modify the program code and insert themselves into it. Find here the best Free Antivirus Software for your Windows Pc How does computer virus enter my system? Even if you’re careful, you can pick up computer viruses through normal Web activities like: Sharing music, files, or photos with other users Visiting an infected website Opening spam email or an email attachment Downloading free games, toolbars, media players and other system utilities Installing mainstream software applications without thoroughly reading license agreements...