Zombies are making a killing on TV (The Walking Dead), in movies (World War Z), and in books (Pride and Prejudice and Zombies). There’s even a zombie game/fitness app, Zombies, Run!
But zombies aren’t so entertaining if your computer becomes one.
In PC terms, a zombie is a computer that’s been taken over without the owner’s consent by a third party (or group of people). Once your computer is among the living dead, it often becomes part of a botnet, or a network of other zombie computers. Rogue hackers control botnets to perform orchestrated denial of service (DOS) attacks and to widely spread email spam and malware, among other misdeeds.
Botnet attacks have been around for a long time but are becoming increasingly more sophisticated. So far this year, there have been several high-profile cases that illustrate the power of botnets. Through the global ‘Pony’ botnet attack, for instance, criminals stole about $220,000 in bitcoins and other digital currencies. And a large botnet recently infected Internet-connected home appliances —including refrigerators!—to send out more than 750,000 malicious emails.
Here’s the really scary part: Your computer could be part of a botnet, and you might not even be aware of it. And if your PC doesn’t have an antivirus protection and two-way firewall, you’ve just increased the chance that your PC could be a zombie. Here are 8 signs your computer might be a zombie, and what you can do to bring it back to the land of the living.
8 Signs Your PC Might Be a Zombie
1. Your computer’s performance is noticeably slower, even when you don’t have many applications open. Criminals want your computer to carry out illegal actions, and those actions require the use of your computer’s processor and network. So if your computer and/or your Internet connection speed have become sluggish, it may be because of a zombie.
2. You receive unexplained error messages.
3. Your computer crashes frequently.
4. You discover messages in your outgoing email folder that you didn’t send. A tip-off might be if you receive bounce-back notifications from people you don’t know or haven’t emailed.
5. It takes your computer longer to shut down and start up.
6. You discover an unexpected loss of hard disk (or flash storage) space.
7. Your Web browser frequently closes for no obvious reason.
8. Your access to computer security websites is blocked.
How to ‘Kill’ a Computer Zombie
If your PC has become a zombie, there may be ways to resurrect it.
• Update your antivirus and/or anti-spyware software and scan your computer’s hard drive to find and remove the malware. Keep in mind some types of malware will prevent your antivirus software from running. In that event, download additional antivirus software and try to run each one until you find a program that will get past the zombie’s self-defenses.
• Often, zombie/bot malware hides from security software scanners by installing a rootkit. A rootkit is a stealth piece of software that’s usually malicious. There are free rootkit detection software programs you can download.
• Set your computer’s personal firewall to its maximum-security level. This will require applications seeking access to the Internet to notify you, enabling you to track all incoming as well as outgoing traffic. In turn, this can help you identify repeated requests from the same application to access just a few destinations—a telltale sign the application is a zombie.
• If that’s the case, do a search of the application’s name to see if others have identified it as malware. Try to create a list of all files associated with the suspicious application and where they’re located on your storage drive. Remove the application and any related files immediately and restart your computer. You may have to do this several times, because one piece of malware may have several variants on the same computer.
• You’re not going to like this one, but here goes: If you’ve discovered your computer is a zombie and want to make sure you’re completely zombie-free, you should completely wipe the hard drive or flash drive and reinstall the operating system and applications. Make sure your important files are backed up first, of course.
• Once you’ve restored your computer’s storage drive, applications, and documents, run your security software again just to make sure nothing is amiss.
Better Safe Than Zombified
If your computer has become a zombie, it’s probably because you clicked on a malicious file attachment or installed an application you weren’t 100 percent sure about.
To reduce the risk of your computer being compromised again, keep your security software running and updated and your personal firewall at maximum level. Check emails with file attachments closely; you can often tell that the sender didn’t actually email it to you by the stilted language, improper spelling, or other signs. Delete spam email messages without opening them. Don’t download applications if you have any concerns about their safety.
If you take these preventative steps, you can spend less time worrying about your computer and more time watching The Walking Dead. That’s the kind of zombie we like.