While doing research on a suspicious neighbor, Ben Sayre went to a website that seemed fishy and later noticed extra buttons showing up on his computer screen. Sayre, a UW-Madison journalism graduate student and victim of a computer virus, said he doesn't do much to protect his computer from future viruses and other malware, or software used for malicious attacks and intrusions.
I worry about it a little, but I feel I can just reinstall the OS [operating system] if it actually makes it hard to use my computer,"" Sayre said.
The downsides to not protecting your computer can reach far beyond the annoyance of reinstalling an operating system, however: unprotected computers leave themselves vulnerable to botnets, or ""robot networks.""
Using a botnet, a hacker or spammer can remotely control a ""zombie army"" of computers, according to the government computer-protection website OnGuard Online, and the owners might not even realize their computers have been compromised.
The website describes how a typical botnet works: a spammer infiltrates an unprotected computer, hides software on the computer or opens up a communication channel and carries out whatever task the botnet creator wishes. This task may range from spying on the user's Internet activity, noting personal information like credit card account numbers or using the computer to send spam.
""Botnets are the latest in a long line of threats that are out in the Internet today,"" said Paul Barford, a UW-Madison computer science assistant professor. ""What makes botnets different from threats in the past is that they enable a single user to marshal computer resources that exist throughout the Internet.""
Botnets can control hundreds of thousands of home computers; some have been reported to control over a million, according to OnGuard Online.
""As a user, sometimes you don't even notice"" the malicious activities your computer is carrying out, said Linda Pruss, a security technologist with the UW-Madison office of computer information security. You might think your computer is just acting sluggish, she said.
To avoid detection, some botnets direct their ""bots"" to send out spam instead of doing it themselves. Thousands of computers delivering spam are harder to identify and block than one, said Brian Dieth, a senior information processing consultant with BadgIRT.
Though hackers hacked in previous years to gain recognition and create mischief, Barford explained the motivation of hackers has changed to one of financial gain.
Botnet owners can leverage their control of computer networks for money from marketing companies and other interested parties. ""They use it as a spam net that someone can purchase,"" Pruss said.
Along with the shifting motivation for creating botnets comes a heightened sophistication of the tools used, Barford said, as economic incentives give botnet controllers a compelling reason to develop more devious botnets.
""Gone are the days when you have a kid trying to hack into a computer,"" Barford said. ""We need to be a lot more worried about malicious things that happen today.""
Barford founded Nemean Networks, LLC, in June to research and combat malicious computer activity, including botnets.
Computer security systems often identify attacks based on that attack's unique ""signature,"" but can miss ones they haven't encountered before or falsely identify something benign as malicious. The Nemean approach, Barford said, gathers information both broad and detailed on malicious activity in computer networks. The characteristics of a signature are more detailed than those used by other methods.
Nemean Networks has teamed up with DoIT to test the company's technology. Barford said he expects to expand tests to well-known companies early next year. He said a consumer version of his product might be available in the next three years.
In the meantime, there are steps students can take to protect their computers. Pruss suggests running an antivirus system, updating your operating system, running a firewall and performing nightly computer scans. It's also best to avoid questionable sites or links, she said.
""One of the first things these viruses try to do is to disable your security system, so don't think you're up to date because you aren't getting [prompted to install] updates,"" Deith said. ""Your system may have been disabled.""
Deith further cautions that students should be careful what information they put on their computers and the Internet, since they might not always be aware who has access to this information.
