The electronic nature of information systems makes them more prone to errors, abuse, and destruction. One reason for this is the network structure of the information systems. Networks consist of computers (clients and servers), that are connected with wires and wireless solutions. This fact makes them vulnerable to physical dangers such as fires, floods, hardware failure, etc. Computer issues are also common such as programming errors, faulty installation and unauthorized changes.
The majority of the danger, however, comes from the Internet. Any traffic circulating through the network can be intercepted during a hacking attack. This vulnerability comes from such communication services as E-Mail, instant messaging, and peer-to-peer networks. They can be used to spread malicious files even without the knowledge of the sender. Their traffic can also be intercepted for data gathering.
Another vulnerability comes from wireless networks such as Wi-Fi and Bluetooth. Free public Wi-Fi hotspots may use specialized sniffer programs that can access the resources of any computer on the network. These are the most common types of malicious software that is used to attack information networks. The first is basic viruses. They are programs specifically designed to execute malicious code without the user’s permission. Viruses often come hidden in Trojan programs that pretend to be legitimate software. The next type is worms.
They are independent programs that copy themselves to every computer on the network. Drive-by downloads are very common today. They install a virus in the background as the user installs a legitimate program or file. A new type of malware known as ransomware has been gaining traction. When executed it encrypts the files on the computer until the user transfers money in bitcoins to a specific valet. These and other types of attacks can be used for identity theft, theft of corporate secrets, denial of service attacks, and other malicious activity.