In a recent blog post, I discussed Distributed Denial of Service (DDoS) attacks and the impact they have on network security. A DDoS attack typically uses hundreds or thousands of “zombie” machines – a horde of compromised computers called a botnet – whose owners have no idea they are being used as weapons of Internet warfare.
Fortunately, though, network users and operators can take certain measures to protect themselves from these attacks. Here are some ways to prevent yourself from becoming just another “bot.”
- Stay up to date. Criminals will target any system that is unpatched or missing updates. Make sure to not only update your computers, but your smartphones, gaming systems and devices such as wireless access points and routers. Many DDoS attacks routinely take advantage of game consoles and home routers that haven’t been updated – but these systems should be updated on a regular basis too. Any of these systems have the potential to be used without your knowledge through taking advantage of unpatched systems.
- Think before you click. Spam and phishing attacks use official-looking emails and web sites in an attempt to lure people in and click a link or open an attachment. But this innocent-seeming action can trigger a malware infection, causing your computer to become another zombie used for attacks. If you’re unsure of whether an email or site is legitimate, try to verify it using other means like a phone call.
- Protect your home network. The vast majority of botnet machines are home users on commercial Internet provider networks. Unfortunately, most commercial ISPs aren’t responsible for maintaining the security of devices within your home. For example, change your router’s default password to something unique, just like you’d change the locks on your front door if you lost your keys. Stay Safe Online maintains this list of other great tips for keeping your personal network secure.
- Turn off unused systems. Is that computer from 2002 still running forgotten in a closet somewhere? Maybe that old router is still sitting on the shelf, unused but turned on? Forgotten systems are a common target for botnet operators and other criminals. When a device has outlived its usefulness, or when its manufacturer is no longer supporting the product, it’s best to shut it down and consider recycling it rather than letting it serve as an unknown zombie in your own home.
- Be suspicious of USB or Flash drives. Another common and well-established way to distribute malware and build botnets is using USB drives and other pluggable external devices. Often, criminals will just leave flash drives lying around at convenient places in the hopes that someone will pick them up and plug them in. Here is a fascinating and cautionary look at how this technique was used in one of history’s most famous cases of cyber-espionage.
These are some of the actions that Internet users and organizations can implement to prevent their systems from becoming unwitting accomplices of cyber-criminals. Combating botnets is an important part of the overall defense against denial-of-service attacks. To stay updated on ways protect yourself online, be sure to follow OARnet updates on Twitter (@OARnet), Facebook and LinkedIn.
