Free Online Spyware and Virus Scanners: Is My PC Infected?

If you haven't heard the news from Sophos, a top computer security firm, it's time you did.

According to the company, one in every 44 emails was viral in 2005, with an unbelievable 48% increase over the previous year. Over 15,000 malware threats were identified. Sophos' report is here.

Photo credit: Pam Roth

Also of interest is the State of Spyware Report from Webroot (free download) that looks at spyware in 2005, which reports that the year was the worst for spyware and the best for cybercriminal.

McAfee released a paper titled "Adware and Spyware: Unraveling the Financial Web," [pdf file] highlighting that adware and Spyware is increasing at an exponential rate. "By August 2006, there were approximately 450 adware families with more than 4,000 variants." The company's SiteAdvisor reported that 97% of Internet users don't know the difference between safe and unsafe sites.

Consumer Reports' State of the net 2006 reports that one in eight U.S. households had a major and often pricey problem as a result of Spyware. The average cost per incident is US$100 with the damage totaling $2.6 billion. "...two of the biggest risk factors for spyware infection were having used Internet file-sharing software, such as Kazaa, and ­having minors at home who go online."

That is bad news indeed, but what's shocking is how many people I know who have many of these viruses, spyware and malware on their computers and don't even know it.

The AOL/NCSA Online Safety Study says 22 percent of users believe their home computers are very safe and 61 percent say their computers are somewhat safe from online threats. 81 percent of home computers don't have one of three critical protections: updated computer virus software, spyware protection or a secure firewall. The good news is that the percentage of American home computers infected with spyware fell almost 20 percent between 2004 and 2005.

So, how can you tell whether you are really safe or not?

Here are some warning signs that you can look for:

• PC is slower. Some operations take longer than normal to run for no apparent reason.
• Opening files full of meaningless numbers.
• Computer connects to the Internet on its own and this isn't normal.
• Computer crashes and restarts itself.
• Very slow Internet connection.

In all of these situations — unless you have a good software toolkit to scan, identify and clean up malicious software that has self-installed itself on your PC — there is little you can do about the situation.

Some viruses have a built-in timer and can sit quietly on your computer for a while before they do any damage. Others can operate without you noticing anything unusual for a long time.

Still others that aren't viruses can create more frustrating situations than some popular viruses like Internet Explorer BHOs, for example.

Some of these nasty issues can be resolved and patched with Microsoft Windows XP Service Pack 2, but many people don't know about these issues or haven't upgraded to SP2 for different reasons.

A good starting point to check for malicious and unnecessary software that might have infected your PC is to use free online spyware detection services. These offer a quick scan and verification of your computer against known spyware and adware.

Just visit any of these "infection auditing" services and let the web-based application scan your computer with a simple click. If viruses or malicious software is found on your PC, the application reports the results and suggests solutions. The solutions depend on the application — some may just tell you the results of the scan, but don't clean it up unless you buy their software.

These are the spyware infection auditing services that I highly recommend visiting from time to time:

Webroot - Spy Audit

TrendMicro - Free Online Spyware Removal Utility

PestScan - The free online spyware detector

ZoneLabs - Online Spyware Scanner

SpywareGuide - Online Scan

Xsoft - Spyware and Adware Scanning

Computer Associates - eTrust PestScan

Panda Software - ActiveScan with TruPrevent

Note: Most of the above are ActiveX applets and may need to run from Internet Explorer. After a short delay while your browser downloads the control file, you get a "Warning Dialogue" requesting permission for the ActiveX-based scanner to run.

Please keep the following in mind:

a) Another study from October 2004 of major anti-spyware programs by PC security researcher Eric Howes shows that "Even the best-performing anti-spyware scanners ... missed fully one-quarter of the 'critical' files and Registry entries."

b) An article in Windows Secrets Newsletter reporting on Howes' study claimed that most anti-spyware programs missed over half of the infected files.

c) Even a combination of the top two programs found only 70% of the spyware on the test computers, according to the article.

d) eWeek writes, "The most popular detection and removal tools 'fail miserably' at addressing the growing spyware/malware scourge."

So, my overall recommendations are:

• Adopt a preventive strategy that uses multiple defense tools.
• Use more than one anti-spyware program.
• Consider enabling encrypted, invisible browsing to help keep your data secure and to avoid phishing, pharming, popups and identity theft.
• Systematically eliminate cookies and temporary files after browsing.

For more support, here are other resources to help. One is a little guide that tells you about the free online spyware scanners. It explains which only identify the intruders and which do the clean up.
http://www.alken.nl/spy.htm

The other is a small comparative list of spyware removal tools:
http://www.comparespywareremovers.com/

PC World's report, Spyware Can Make Your PC Lie to You, discusses Webroot's report on the state of spyware in 2005.
http://blogs.pcworld.com/staffblog/archives/001448.html

StopBadWare.org is a "neighborhood watch" campaign that fights back against adware, or rather "badware" as it calls them. This site from Harvard Law's Berkman Center for Internet and Society provides objective information regarding badware and a collection of research on the topic.

The last one is a full guide to spyware software that provides an all-inclusive and updated resource on spyware applications, what they do and how they're used. These resources include which software applications can detect and defeat spyware, an extensive database of all known spy software and adware applications, contact information and information on other privacy-related products: http://www.spywareguide.com/

Sophos glossary of terms.

What other online tools do you suggest? What have you found effective?

Updated: January 26, 2007