Distributed denial-of-service (DDoS) attacks.

What it is:

A distributed denial-of-service (DDoS) attack — or DDoS attack — is when a malicious user gets a network of zombie computers to sabotage a specific website or server. The attack happens when the malicious user tells all the zombie computers to contact a specific website or server over and over again. That increase in the volume of traffic overloads the website or server causing it to be slow for legitimate users, sometimes to the point that the website or server shuts down completely.

It could be possible for malicious users to use your computer in one of these attacks. By taking advantage of security vulnerabilities or weaknesses, an attacker could take control of your computer. He or she could then force your computer to send huge amounts of data to a website or send spam to particular email addresses. The attacks are "distributed" because the attacker is using multiple computers, including yours, to launch the denial-of-service attacks.

What it can do:

The most common and obvious type of DDoS attack occurs when an attacker “floods” a network with useless information. When you type a URL into your browser, you are sending a request to that site's computer server to view the page. The server can only process a certain number of requests at once. If an attacker overloads the server with requests, it can't process yours. The flood of incoming messages to the target system essentially forces it to shut down, thereby denying access to legitimate users.

What you can do:

There are steps you can take to reduce the likelihood that an attacker will use your computer to attack other computers:

• Install and maintain anti-virus software.
• Install a firewall, and configure it to restrict traffic coming into and leaving your computer.
• Follow good security practices when it comes to maintaining your contact or email lists. Applying email filters may help you manage unwanted emails, by automatically processing incoming messages based on certain criteria that you set.
• Be cautious if you notice that your Internet connection is unusually slow or you can't access certain sites (and that your Internet connection is not down).
• Avoid opening email attachments, especially if they are from people you don't know.

If you believe you are a victim of a DDoS attack, contact your Internet Service Provider, as they will be able to help mitigate.

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