If you get a file from a site you don't know very well (like a game or a screensaver), the first thing you should do is scan it using an antivirus. The problem is that your antivirus might not be very good or might not include the signature of the trojan included in the file you've just downloaded. So a good idea is to have a second opinion, but you can't install more than one antivirus (unless you disable the real-time protection).
VirusTotal is a site where you can upload a file smaller than 10 MB and it will be scanned by a large number of antivirus software (the current number is 31), including: Kaspersky, BitDefender, F-Secure, Panda. The file will not be scanned instantly, but you'll have to wait a short time (usually around one minute), depending on site's load. You'll get a report like:

If you see conflicting responses, look at the most trustworthy engines (
some tests) and at the number of engines that report a virus. In the situation depicted in the screenshot, I can safely assume that the file is clean.
The service is available by email too: send a mail to scan@virustotal.com with the subject SCAN. If you use Gmail, you'll have to rename executable files (for example, from setup.exe to setup.ex1) to be able to send them.
A similar service is
Jotti's malware scan, that has a bigger limit for the file size: 15 MB, but uses less antivirus engines.
{ Thank you, Google! }
Labels: Security, Tips
digital said on April 11, 2007 2:09 AM PDT:
hi,
just wanna ask if which do you think is the best antivirus software around?
Thanks
From my limited experience with antivirus software, I'd say
Kaspersky is the best. It's very good at detecting malware, it doesn't use too many resources and it also has a lot of advanced features. Unfortunately, it's not free, but there's
a free version from AOL (I didn't try it, but I suppose it has less features).
A very good free antivirus is
AntiVir.
said on April 11, 2007 2:50 AM PDT:
Kaspersky Is my first choice, I don;t run windows But I have before and kaspersky is the best around. Fsecure comes next because it uses kasperskys signatures meaning basically they are the same product. Bitdefender is third and Symantec is LAST! everything between bitdefender and symantec is whatever I missed.
thanks a lot. I just translated & edited your post to
Traditional Chinese, just let you know.
Btw, Jotti's malware scan use 17 anti-virus engine, more than that of VirusTotal
VirusTotal - 31 AVs
Jotti - 17 AVs
But Jotti seems busier than VirusTotal. On the other hand, Jotti uses AJAX, while constantly refreshes the page.
said on April 11, 2007 5:13 AM PDT:
Symantec Anti-Virus Corporate is the best.
said on April 11, 2007 11:58 AM PDT:
Google sent in a tip for this?
I'm glad that somebody noticed the last line. I found about the service from a Google report:
"The Anatomy of Clickbot.A" (PDF, 123 KB).
John said on April 11, 2007 1:16 PM PDT:
I was going to test this out... It's a great idea, but waiting 11 to 17 minutes for the scan to start is a bit too long for me.
I've got one word for somebody who is worried enough about a file that they are willing to wait upwards of 20 minutes to find out if it has a virus or not: "Abstinence".
It depends. Sometimes you wait 2-3 minutes. But imagine how hard would be to download and install 30 programs and scan a file using each one. I bet it would take hours. And it's not a viable solution.
said on April 11, 2007 3:07 PM PDT:
Nod32, hands down. Just do some googling and you'll see the same opinion on most reputable sites.
said on April 12, 2007 8:27 AM PDT:
I found a
"Malware Removal and Prevention" guide that links to a lot of tools that detect and remove viruses, trojans and spyware. I especially like
Superantispyware. Some of its features:
* Quick, Complete and Custom Scanning of Hard Drives, Removable Drives, Memory, Registry, Individual Folders and More! Includes Trusting Items and Excluding Folders for complete customization of scanning!
* Detect and Remove Spyware, Adware, Malware, Trojans, Dialers, Worms, KeyLoggers, HiJackers, Parasites, Rootkits and many other types of threats.
* Light on System Resources and won't slow down your computer like many other anti-spyware products. Won't conflict with your existing anti-spyware or anti-virus solution!
* Multi-Dimensional Scanning detects existing threats as well as threats of the future by analyzing threat characteristics in addition to code patterns.
* First Chance Prevention examines over 50 critical points of your system each time your system starts up and shuts down to eliminate threats before they have a chance to infect and infiltrate your system.
Smith said on January 26, 2008 10:30 PM PDT:
Thank you for the good posting. I've read about this from other people's view and opinion. I have personally used AVG Anti-Virus , only for the free version as i could not afford to have a full version one. Nowdays, i prefer to used Bitdefender as it is more user friendly, using less computer resources & very useful functions.
Thank you again.
Having an anti-virus software doesn't mean your computer is already safe. The most important thing is keeping it up to date and make sure you have the latest virus pattern updates without these your anti virus with be useless.
Nice post, I feel this is important for me to have good and powerful antivirus for my computer, and from your article now i have more overview how to protect my computer
Thank's
Jamber
grot said on August 20, 2008 6:59 AM PDT:
Want to know what the best spyware removal tool is? Visit the Best Spyware Remover website to find out and for a limited time you can also download a free report entitled- "PC Protection - Keeping Your Computer Clean and Your Identity Safe".
said on November 20, 2008 5:01 PM PDT:
I have found that Avast is really effective especially when you tweak the On-Access Protection (Instant Messaging, P2P Shield, Web Shield, etc). I also use Superantispyware. Overall, I'd say use as many reliable tools as referenced by "soldiers in the frontlines" and always keep your "toolbox" updated. We live in perilous times; zero-day malware and bright programmers using their intelligence to wreak havoc.
TP//SLU
Antivirus said on October 29, 2009 1:33 PM PDT:
While this sounds great in theory, I wonder how practical it is. It is rarely the case that you can identify a mysterious file and then scan it for viruses. Typically if it is suspicious you would just delete it. It is the ones that sneak by you, and you never have the chance to vet, that cause the real damage. Still, this app has its heart in the right place and I can see some, though limited, applications for it.
@Antivirus:
Let's say you have an antivrus software that flags one of your files as malware, but you're not sure whether to trust the application. Or let's say you see a strange process in the task manager, your antivirus says it's not infected, but you want a second opinion.
Antivirus said on December 18, 2009 12:00 PM PDT:
Alex - I just had to reinstall my OS because my computer was locking up due to some corrupted system file caused by malware. I was running Avira the whole time. I cannot ever know what was causing the problem because I was never alerted at all. I don't believe that any AV can catch all bugs, and this proves it. This is why we need a strong Cloud AV with good community support. You just cannot rely on the companies to roll out definitions with any reliability.