Tens of thousands of computers are infected with some type of botnet or 'bot' and computers that have been infected are generally referred to as 'zombies.' A zombie is a computer that has been infected with malware, allowing an attacker to gain complete control which is a security threat.

These criminals are able to access lists of 'zombie' PC's and activate them to help execute denial-of-service attacks against various websites, host phishing attack sites or send out spam email messages. If anyone tries to trace an attack back to the original source, they will find a victim rather than the criminal because they are so clever.

How do you know if your computer is infected? If you notice anything odd as you are working, such as a slow computer or a computer that seems to slow down or crash for no reason, there might be some malware running in the background. You need to scan your computer with current versions of your antivirus software, to detect malware. Zombies can be used extensively to send out email spam.

In fact an estimated 80 percent of all spam worldwide was sent by zombie computers. This is what enables spammers to avoid detection. It is spam that also greatly furthers the spread of Trojan horse computer viruses, which rely on the movement of emails or spam to grow.

They can be used to conduct distributed denial-of-service attacks, where a large number of zombie computers make simultaneous requests of a website's server with the intention of crashing the server thereby preventing legitimate users from accessing the website.

There is a variant of this type of attack known as distributed degradation-of-service. Committed by "pulsing" zombies, distributed degradation-of-service is the moderated and periodical flooding of websites, done with the intent of slowing down rather than crashing a victim site. The effectiveness of this tactic springs from the fact that intense flooding can be quickly detected and fixed, but pulsing zombie attacks and the resulting slow-down in website access can go unnoticed for months or years.

To protect yourself, you need to make sure to have the latest anti-virus software, install firewalls, and make sure you always delete suspicious email messages. Cloud technology automatically stops viruses and spyware before they reach your computer. It's a whole new way to protect your computer and it won't slow you down.

Antivirus software should have the following features:

- Only real-time updates to safeguard you from the latest online threats today and in the future
- Light on system resources so your PC runs faster. - Is designed to be easy-to-use and understand with simple screens and graphical reports.
- It also should block spam.
- Has parental controls keep kids safe online.