How to Detect If Your Computer is a Zombie

The FBI has recently launched their "Operation Bot Roast" which aims to help fight identity thieves, hijackers, and botherders. These "botherders" use botnets to take command of other people's computers.

So what is a "bot" or "botnet"? Symantec's site has an explanation. Bots are similar to Trojans and worms but they perform automated tasks for their master (the cybercriminal or the one who infected your computer). These tasks can range from spamming to "denial-of-service" attack. A botnet on the other hand, is a large collection of computers infected by "bots" controlled by a "bot herder" usually through an IRC server. When your computer has been remotely controlled by a "bot herder", it is now a Zombie. Most computer owners are not even aware that their pc has been infected.

Signs that your computer is a zombie

The Washigngtonpost.com has previously released an article on how to tell that your computer may be infected by a "bot". These signs include, poor computer system performance, slower response times and longer start-up and shut-down times, dramatic loss in Internet connection speeds, loss of hard disk space, web browser frequently closes for no apparent reason, browser's home page resets and cannot be changed, new desktop icons and applications, like toolbars, suddenly appear, access to various computer security-related Web sites is blocked, pop-up ads appear even when the Web browser is closed.

Other signs also include, computer seems to be accessing the hard drive constantly, an unresponsive mouse and keyboard, when you open your email there are several bounce notifications from people you never tried to email, there is internet activity or your modem's activity light continuously flashes even when you're not even accessing the net, your virus checker is disabled and you're unable to update your antivirus program.

How did you become infected?

Bots can infect a computer in many ways. One of the most common is that Bots spread themselves through the internet by searching for unprotected computers. Sometimes, it is downloaded to the computer by a Trojan, or installed by a Web site with malicious codes, or when it is emailed directly by a person whose computer is infected by a Bot. In recent cases, bots spread themselves through various instant messengers. An infected computer sends a URL through their buddy list and when the recipient clicks on that site, they will be infected. The computer may also be compromised through vulnerabilities in the Internet Explorer, or when a person's Internet Explorer zone settings is unsecured, or when the user allows Internet Explorer to install a program by clicking "OK" when a dialogue box appears.

Knowing how your computer got infected is a good way to prevent your computer from being compromised in the future.

Prevention is better than cure

The FBI, in order to raise the public profile of the botnet issue, is encouraging people to take the basic steps to protect their computers. These include installing antivirus software, firewall, using strong passwords, and a good email and download behavior.

One should never scrimp on an antivirus program once they have acquired their computer, computers breakdown because of virus infections so it is better to invest in a good antivirus program to prevent any future problems. If an antivirus software is not in your budget, consider some of the free antivirus programs like the AVG Antivirus Free Edition. You can also scan your computer frequently using online antivirus scanning provided by either Trendmicro or Mcafee. As for firewall software, www.download.com has a collection of some free firewall software. The most popular is ZoneAlarm 7.0, it is top rated by CNET Review and has a good user rating.

You should also try to download Microsoft windows patches regularly and only download software from trusted websites.

SOURCE:

Brian Krebs, Cybercrook delivers trouble. Washingtonpost.com. URL: (http://www.washingtonpost.com/wp-dyn/content/article/2006/12/26/AR2006122600922.html)
http://www.oeupdates.com/Zombie-Computers.html
http://en.wikipedia.org/wiki/Botnet
http://www.symantec.com/avcenter/cybercrime/bots_page1.html