Keep a clean device

Viruses
Viruses are harmful computer programs that can be transmitted in a number of ways. Although they differ in many ways, all are designed to spread themselves from one computer to another through the Internet and cause havoc. Most commonly, they are designed to give the criminals who create them some sort of access to those infected computers.

Spyware
The terms "spyware" and "adware" apply to several different technologies. The two important things to know about them is that:

1. They can download themselves onto your computer without your permission (typically when you visit an unsafe website or via an attachment).
2. They can make your computer do things you don't want it to do. That might be as simple as opening an advertisement you didn't want to see. In the worst cases, spyware can track your online movements, steal your passwords and compromise your accounts.

Botnets
Botnets are networks of computers infected by malware (computer virus, key loggers and other malicious software) and controlled remotely by criminals, usually for financial gain or to launch attacks on website or networks.

If your computer is infected with botnet malware, it communicates and receives instructions about what it’s supposed to do from “command and control” computers located anywhere around the globe. What your computer does depends on what the cybercriminals are trying to accomplish.

Many botnets are designed to harvest data, such as passwords, social security numbers, credit card numbers, addresses, telephone numbers, and other personal information.  The data is then used for nefarious purposes, such as identity theft, credit card fraud, spamming (sending junk email), website attacks, and malware distribution.