They’re nasty, elusive and destructive. Collectively, we refer to them as malware: dangerous types of computer code or programs designed to harm your Mac and your files. Each category of malware behaves differently, and the specifics of the individual attacks are as unique as the malicious code writers themselves. Read below to learn more about the types of malware and other threats that plague Macs.
Viruses are the common cold of computers: easily spread and often misdiagnosed. The word “virus” is frequently misused in describing other forms of malware. Actual viruses are a small bit of executable code that spreads when users open infected files or applications. Viruses that infect Mac apps are actually rare amongst today's malware, although file-infecting macro viruses remain a problem.
A Trojan horse is like a college roommate that seems cool at first, until they stop paying rent, eat your food, leave dirty clothes everywhere, and steal from you. Trojans enter under the pretense of usefulness, but actually contain malicious code or exhibit unwanted behavior. Trojan horses are the most common type of Mac malware today.
Worms are like the elusive varmint scurrying through the insulation in your wall. Because they don’t need to attach themselves to an existing file or program, they can be very difficult to find. A type of virus, worms spread over networks, and can carry out malicious actions once they find new hosts.
Spyware is like a creepy neighbor—or someone sitting in an unmarked van outside your house—that stares into your window and shuffles through your mail. It often enters your Mac as a Trojan horse and then secretly monitors your computing behavior, collecting personal information such as your surfing habits. It may even record everything you type, including passwords and credit card information.
Spam is the mosquito of the computer world: annoying and ubiquitous. A single spam message can be dealt with easily enough, but en masse it can crowd your inbox and cause a significant loss of productivity. Spam can also contain malicious links or attachments that can infect your Mac, or can trick you into signing into a fake site and unknowingly giving your passwords to the bad guys.
A botnet is like an army of zombie computers bent on destruction. Your Mac could be forced to join the zombie army as a consequence of a malware attack. The network of compromised computers is then used to send spam or to attack other computers.
An exploit is like a schoolyard bully that zeroes in on your weaknesses. It’s a piece of software, a chunk of data, or a sequence of commands that takes advantage of a bug, glitch or vulnerability in order to break through your Mac’s security defenses.
