What Is Malware and How Does It Affect My Computer?
Malware is invasive software code designed to infect or disrupt devices and services. Hackers use malware to steal sensitive data (passwords, financial information), encrypt files for ransom, gain remote control of an infected device, install additional malware, or attack other devices on the same network. Malware attacks aren’t limited to Windows PCs — Apple Macs and mobile devices are susceptible, too. Malware can also slow a device, trigger unwanted ads, or even hijack the device to mine cryptocurrency.
The first modern malware attack may have occurred in 1982 with the Elk Cloner virus, deployed against Apple II systems via floppy disk. In the 1990s, Microsoft’s Windows operating system and built-in applications became the most popular target for malware attacks. As viruses spread, hackers began writing infections in “macro” language to hide within Word document templates and programs. Worms, which are similar to viruses but self-replicate, and Trojans, which represent themselves as something useful to trick victims, also became widespread.
Cybercriminals also developed rootkits, which hide malware on a device and change standard operating system processes. With a rootkit, attackers can take complete control of an infected device and steal data, spy on a victim’s activities, and install additional malware.
Other types of malware include spyware, which collects personal and sensitive data without a user’s consent and can be used for identity theft. Adware bombards users with advertisements, most of which are in the form of popups, and can slow a device. Cryptojacking hijacks a device’s processing power to mine cryptocurrency, and has become increasingly popular with cybercriminals. Hackers can use botnets to control large numbers of infected devices for attacks like distributed denial-of-service, spam distribution, and cryptocurrency mining.