The term malware comes from the words "malicious" and "software," which refer to "malicious software," that is, any software or program designed to be harmful or malicious. The damage or impact can vary depending on the type of malware and its purpose, which is why we need to classify them.
There are several classifications, and they differ greatly. We'll explain the most common ones:
Adware
Its purpose is to display ads in an attempt to trick you into installing other software or, otherwise, to steal information from you through deceptive forms and sites.
Spyware
Its purpose is to monitor a device's activities and send a report. It is a type of silent malware that runs without the user's authorization.
Viruses
It is usually attached to another program or file. When it is run, the virus is activated and begins to replicate to other files or programs to stay alive on the computer. Its objective is to delete or destroy information.
Worms
They are similar to viruses; they seek to replicate to stay alive. The difference with a virus is that a worm seeks to spread across a network to infect other computers and does not need to be attached to a file or program to spread. Its objective is to destroy information.
Trojans
They masquerade as another program to trick the user into installing it. Their objective is to be used as a means of infection with other threats such as viruses, worms, spyware, ransomware, keyloggers, or rootkits.
Ransomware
It retains information, blocks the user's access to the device, encrypts files, and then demands a ransom for that information.
Rootkit
It's similar to spyware; in addition to monitoring and reporting the user's actions, it also allows users to take control of the computer or cell phone.
Keylogger
This records everything a person types, usually to share it with the attacker. It's a technique for acquiring data such as usernames and passwords.
Exploits
This type of malware exploits errors or bugs in the code of other software. If a program has an error in how it was programmed, an attacker can create another program (exploit) that takes advantage of the vulnerability to cause damage.