Network News

X My Profile
View More Activity

Online Anti-Virus Scans: A Free Second Opinion

Periodic online virus scanning is a good idea for Windows users, even for people already using up-to-date anti-virus tools. There are a couple of reasons I suggest this: First, anti-virus software is frequently slow to spot new threats. Take a gander at the daily "unrecognized" stats posted by, which tracks the performance (or lack thereof) of several popular tools in spotting new variants. That list currently examines the performance of several free programs, but the reality is not much different with the commercial tools. Just have a look at performance metrics and virus detection failure rates chronicled here and here.

The second reason follows from the first: If something nasty does make it past your security defenses, usually the first thing it will try to do is disable the active protection and update features in those tools. In such cases, you probably would not know about the infection unless you turned to a third-party program that is not already installed on your computer.

In my experience, two of the better free online anti-virus scanners are Panda Software's PandaScan and Kaspersky Lab's Free Virus Scan. Both require that you run the scans using Internet Explorer, as both require the installation of an ActiveX plug-in to do the job.

F-Secure Corp., CA and BitDefender also offer free online scanners that also use IE and ActiveX, but I haven't yet tried those so I can't offer an opinion on them.

TrendMicro's HouseCall service lets you install and run a free scanning tool from inside an IE or Firefox browser. However, I found the program both annoying -- it emitted a series of very loud and startling tones through my computer speakers while downloading virus definitions -- and ineffective. It crashed halfway through the scan, taking all of my other open Firefox windows with it, including an earlier, unsaved version of this blog post. (I had hoped Firefox 2.0's crash-recovery feature would save what I had typed as it had in previous crashes, but no such luck this time.)

If you have just a single file or archive that you'd like to scan, I'd suggest submitting it to VirusTotal, a free online anti-virus engine that will scan your submission against more than two dozen of the most well-known tools.

Depending on the speed of your PC and the number of files and hard drives you have, conducting an online scan can take between a few minutes to several hours to complete. It's not a bad idea to run the scan only when you can afford to be away from the PC for a few hours, or perhaps right before bedtime. Even on my test machine -- which sports a 2.2 GHz processor and 2 gigabytes of memory -- running several of the online scanners interfered with the simplest of tasks, such as composing an e-mail.

By Brian Krebs  |  March 9, 2007; 10:53 AM ET
Save & Share:  Send E-mail   Facebook   Twitter   Digg   Yahoo Buzz   StumbleUpon   Technorati   Google Buzz   Previous: Patch Reprieve for March's Black Tuesday
Next: QuickTime Security Update Taxes Some Mac Users


Are these on-line scans secure? Are we exposing ourselves to greater risk by installing ActiveX?

Posted by: 22046 | March 9, 2007 1:38 PM | Report abuse

22046 - There's little to be worried about. If the prospect of having another ActiveX control sitting around your machine after the scan is done, simply remove it or disable it: In IE (7) go to Tools, Internet Options, then Programs, and then click on the Manage Add-Ons tab.

Posted by: Bk | March 9, 2007 1:47 PM | Report abuse

Panda disn't work with Vista Ultimate.

Posted by: bbirdy202 | March 9, 2007 2:16 PM | Report abuse

Does anybody know if this something that should be done while logged on as the administrator or can it be done as a limited user? What about program updates in general, does running as a limited user ever cause problems? thanks all.

Posted by: IR | March 9, 2007 4:01 PM | Report abuse

"Does anybody know if this something that should be done while logged on as the administrator or can it be done as a limited user?"

a limited user isn't guaranteed to have the necessary access to read the entire disk... online scans are going to run in the context of the current user and therefore be limited in the same way as the current user...

Posted by: kurt wismer | March 9, 2007 4:24 PM | Report abuse

Kurt is correct. And what's more, many of these scanners require the installation of components to your system that require you to be running as admin.

Posted by: Bk | March 9, 2007 4:56 PM | Report abuse

It seems irresponsible to leave your machine plugged into the network if it's infected with viruses or other malware.

Shouldn't you boot it off of a CD and scan it that way?

Posted by: burke | March 9, 2007 5:19 PM | Report abuse

I ran PandaScan. It found some tracking cookies but it didn't allow me to remove them. When I clicked the button to remove (or whatever it was called), I was taken to their site where I was told I could do that by paying them $12.95 for 6 months of service.

Kaspersky's didn't do anything after the Active X was run.

Posted by: Anonymous | March 9, 2007 8:07 PM | Report abuse

Color me stupid but I thought free meant you didn't have to pay for it. Panda tells me I supposedly have over 900 issues and then wants to charge me for the luxury of removing them without really telling me what, if anything, they are. If Kaspersky isn't going to discover anything at all, like someone else has stated above, then I'm not sure this article has produced anything more than free publicity for a few companies.

Posted by: Miss V | March 9, 2007 9:06 PM | Report abuse

I agree with Miss V. How can you recommend Panda when they want to charge for the "supposed" spyware, etc. they locate? Thats not free!

Posted by: Rick | March 9, 2007 9:37 PM | Report abuse

I ran PandaScan, after having serious problems with sluggish webpage loading and not finding any other solution. It found spyware that Spybot and Ad-Aware hadn't found. I asked PandaScan to show me the log or list (the button next to the button you click to find out how to remove the junk), saved it to my documents, and was able to open it and print it. Most of the spyware was in one file, from when I had flirted with Mozilla/Firefox and hadn't liked it, and I was able to remove them by just deleting the file. My loading speed is back to normal.

While I am not inclined to buy Panda, I am grateful to Mr. Krebs for posting the link to the site, because I found the free scan useful.

Posted by: vklip | March 10, 2007 7:55 AM | Report abuse

I'm using BitDefender and it does an excellent job, give it a try. What I like the most about it is that it will actually clean whatever it finds.

Posted by: rd | March 10, 2007 9:10 AM | Report abuse

I have run Panda's free scan many times in the past and on many machines, and have never been asked to pay for removal of any threats found. They must have changed their policy on that. My apologies.

Posted by: Bk | March 10, 2007 9:14 AM | Report abuse

if you don't know how to remove tracking cookies by manually deleting the files yourself, maybe you should buy Panda's program

Posted by: OhioMC | March 10, 2007 11:11 AM | Report abuse

For what it's worth. You can get Kaspersky 6 for free (under the aol brand name), by going here:

I've been running it for a few months now and it seems to work very well.

Posted by: Kungpao | March 10, 2007 1:12 PM | Report abuse

You should be more careful about recommending free virus services. Panda is one of a very large number of "come-on" services online that offer scans and then charge you an arm and leg to remove any virus found. Besides, when I ran PandaScan, it uploaded not only Active-X to my computer, but some other weird program called "motor" which immediately opened up a browser tab with, surprise, the logon page to my SmithBarney brokerage account.

Posted by: Aussie | March 10, 2007 5:07 PM | Report abuse

Microsoft has 2 versions of their Live OneCare. One is a fee/subscription-based software. The free version is an online scanner.

Judging by reviews of the paid version of OneCare, it may be best to avoid both versions.

OneCare came in last in PC World's review:,129521-c,antivirus/article.html

Neil Rubenking of PC Magazine reports that One Care can eat your email:

Good luck.

Posted by: Al | March 10, 2007 6:13 PM | Report abuse

I actually just wanted to add that the HouseCall scan crashed for me halfway through as well. (I'm using firefox)


Posted by: James | March 11, 2007 3:47 AM | Report abuse

I'm running Win2k Advanced Server on home PC. When I attempt to install Avg, Avast, and Avs, I get an error that this version of OS is not supported. DO you have any suggestions for free anti=virus that will run on Win2K Advanced Server? Thanks in advance

Posted by: rick_atlanta | March 11, 2007 1:35 PM | Report abuse

I have just spent an hour trying to access Panda and kaspersky. Neither would respond to my xpsp2, in ie7, and I am thinking that may mean I'm loaded down with sypware strong enough to block them. I run AVG Spybot and Adaware frees, all of them today.
Obvious I need help - any out there?

Posted by: dijit44 | March 13, 2007 3:40 PM | Report abuse

Another gripe about PandaScan (a minor one) before you even get to scan, you have to sign up for their spam-mail. I've got a yahoo account I use for such things, but how many people are going to be filling the bandwidth with more spam simply because they wanted to be virus free.

Bad panda! No bamboo!

Posted by: WB | March 15, 2007 2:10 PM | Report abuse

Trend Micro's Housecall has gone from best to worst. In the old days it was great but I haven't been able to get it work on any machine for months. And that includes trying both the ActiveX and Java versions.

Panda's offerings are a bit confusing.

They have two free online virus scanners. Both are ActiveX based. Both claim to scan for viruses and Spyware. The older one is ActiveScan. The newer one is available at The new one is sometimes called NanoScan and other times called TotalScan. Both the product name and the application are both in beta. ActiveScan requires an email address before scanning, TotalScan does not. ActiveScan used to remove viruses, I haven't tried lately.

In addition, they also have a dedicated online Spyware scanner called Spyxposer.

Posted by: Michael Horowitz | March 16, 2007 4:08 PM | Report abuse

I higly recommend you to visit this website:
I have runned it and it as eliminated all security threats found on my pc, completly free of charge.
I doesn't work with firefox, since it is an active x, and you will have to provide a valid e-mail adress, but it is the best option I found so far.

Posted by: Rui Pacheco | March 21, 2007 7:12 AM | Report abuse

Are there any free virus scans for OSx based machines?

Posted by: ike | March 28, 2007 4:47 AM | Report abuse

Really we are happy by using this software

its very useful to scan pcs for virus and spyware

and we are planning to purchage your software


Posted by: sreenivasulu puli | April 3, 2007 8:37 AM | Report abuse

There's a very much longer list of online scans at

Unclear which ones are the best though

Posted by: lusher | April 5, 2007 11:24 AM | Report abuse

i wany to gey anti-virus that i will not have to pay for to clean and check my computer

Posted by: Diane | April 8, 2007 4:37 PM | Report abuse

The comments to this entry are closed.

RSS Feed
Subscribe to The Post

© 2010 The Washington Post Company