IT for Donuts: what is a botnet?

By: John McGarvey

Date: 6 June 2014

IT for Donuts: what is a botnet?/ Picture of a botnet{{}}IT for Donuts is our regular Friday feature where we explain a tech term or answer a question about business IT.

This week, find out what a botnet is.

Botnets: malicious networks

A botnet is a network of computers, servers or other devices that have been infected with malware or compromised in some way.

These computers may be scattered all over the world, but they’re linked together via the internet.

Botnets are created when individual computers get infected by malicious software. It’s just like catching a computer virus via an infected website, email or software.

If your computer is part of a botnet, you may have no idea. Botnet software conceals itself and may only use your computer’s processing power when you don’t need it.

Botnets can consist of thousands or millions of computers. For instance, until security experts took it down, the ZeroAccess botnet consisted of over 1.9m slave computers.

What are botnets for?

The hackers and online criminals who create botnets use them to gain access to enormous computing power and distributed internet connections.

Botnets are powerful tools used for many malicious purposes. For instance:

  • Click fraud. Botnets are used to generate artificial clicks on online adverts, so advertisers receive more revenue.
  • Distributed denial of service (DDoS). Because every computer in a botnet is connected to the internet, they can be used to target a specific website with a massive amount of traffic, taking that site offline. Learn more about DDoS >>
  • Sending spam. Botnets are often set up to distribute enormous quantities of junk email.

Botnets are an important tool for online criminals. Stamping them out would be enormously beneficial for the internet as a whole.

To do your part, take good basic security precautions. Use decent security software. Avoid opening emails and files that look suspicious.

Finally, pay attention if your computer starts behaving oddly. If it slows down or seems to be hard at work while you’re not using it, double-check your security software and perform a full system scan.

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