BitDefender QuickScan: Lightning fast cloud-based malware scanner for quick, on-the-fly security checks

Ever try to use traditional, clunky online malware scanners to try to get a second opinion as to if your computer is clean or infected with malware? I have, and I can attest to the fact that it isn’t pretty. While in theory online malware scanners can be useful, in reality online malware scanners are typically nothing more than gimmicks. They are slow and clunky; and often they can only detect – not remove – malware. Indeed, many times in the past I have accidentally closed an online malware scan in-progress because it was taking so long that I forgot about it; other times – when scans did finish – I would feel cheated because I invested so much time into scanning my computer and in the end the scanner could not remove the malware. BitDefender is looking to change that with their QuickScan.

BitDefender QuickScan is a free online malware scanner that leverages the power of the cloud to conduct lightning fast malware scans. How fast are we talking here? Is seven seconds fast enough for you? Yeah, I thought so. While the actual scan time will vary depending from computer to computer and the current load on BitDefender’s servers, all the scans I have conducted with BitDefender QuickScan have finished in under two minutes, with the fastest one being seven seconds.

I know what everyone reading this article must be thinking right now: “Scans that fast? It must be a scam!” No, it isn’t a scam. There are multiple contributing factors as to why BitDefender QuickScan is so, well, quick:

  • BitDefender QuickScan does not scan your whole computer. It only scans programs/files in active memory (i.e. currently running programs/files or programs/files that have recently been run) and programs/files that run at Windows startup.
  • Not all programs/files in active memory and Windows startup list are scanned. Programs/files are filtered by extension, and file types “deemed harmless” are skipped.
  • QuickScan uses cloud technology to conduct the scanning/detection process:

In a nutshell, QuickScan makes a list of digital fingerprints (or hashes) of the programs that are running and of other critical files. It then sends this list to the server. If the server doesn’t recognize a hash, it requests the file to be uploaded so it can be thoroughly analyzed. When the analysis is complete, the server returns a .clean. or .infected verdict for every file in the list.

The first time you run QuickScan on your system it may find a lot of .unknown files, so it’s normal for the scan to take longer. After using QuickScan a few times you will notice that it becomes faster and faster. This is because once the server receives and scans a new file, it will subsequently recognize it by its hash and never request it again.

With such a limited scope, BitDefender QuickScan must be useless, right? Wrong. You see the point of BitDefender QuickScan is not to ensure your computer is 100% clean. If you think you can depend on QuickScan to keep your computer malware free, you need to think again. The point of BitDefender QuickScan is to conduct quick, on-the-fly scans that provide a second opinion as to if your computer is infected or not. Obviously since QuickScan only scans in active memory/startup list it does not detect “dormant” malware; it only finds malware that is active at the time of the scan.

That said, it must be noted that BitDefender QuickScan only scans and detects malware – it does not remove it; you need to use your installed security programs to remove any malware that is found. In fact, according to BitDefender, QuickScan does not modify any files on your computer:

Quickscan does not modify or delete any file on your system and only uploads executable files for checking (i.e. NO documents or other data files are sent).

It obviously would be nice to be able to use QuickScan to remove malware in addition to detecting it; however, personally speaking, for scans that literally take less than a minute I don’t mind not having removal capabilities.

BitDefender QuickScan works in Internet Explorer, Firefox, and Chrome and using it is as easy as visiting the homepage and clicking the FREE SCAN NOW button; at the end of every scan you are told if your computer is infected or not and you are allowed to view a full report of QuickScan’s findings.

The first time you run QuickScan you will need to download an add-on for Firefox and Chrome, while Internet Explorer users will need to download the ActiveX component. After you have the Firefox/Chrome add-on installed, you don’t even need to visit the QuickScan homepage anymore – you can run the scanner by clicking on the QuickScan icon in your browser toolbar.

Ready to give BitDefender QuickScan a whirl? You can access it from the following links:

Version reviewed: Firefox add-on v0.9.9.52, Chrome add-on v0.9.9.63, Internet Explorer ActiveX control v0.9.9.62

Supported OS: Any Windows that supports Firefox, Chrome, and Internet Explorer

BitDefender QuickScan homepage

[Firefox add-on page]

[Chrome add-on page]

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  • meldasue

    This will be useful for helping friends to clean up their computers. (‘Wah! Windows is crap!’ No, it’s the crapware you keep installing on it.) So many of these scans are malware themselves, it’s good to have one bookmarked for recommendations/later use. And it was fast…..

  • Shades

    Hey Ashraf,

    I know you wrote this a while ago, but I just tried it and got no report, but got a big red notice that 1 item had been found, saying click here. That took me to a download page of all the options, which were to download and install their softwares. I noticed that you said that I could also have it do a full scan, so I went back and clicked on online scans, thinking I would be presented with that option. Instead, it ran the same scan as before, this time saying it was not infected. Any idea what just happened? Did it remove the infected file? Why did I not get a report naming the file, as you seem to suggest?

  • JCR1960

    77 secs to scan a fairly well loaded system…But is proficient? Ah, bah, we’ll know sooner or later….people are gonna talk about this on the net. It can’t hurt, can it? Keepin’it till proven useless. (syst. clean, BTW)
    Nice set of freebies since your return, Ashraf….Many thanks ;-)
    On second thought, I don’t believe a comp. with BitDefender’s reputation would ruin it by making a sloppy service available.

  • janetb


    If I had a serious or life-threatening disease, I would probably get the opinion of two or three specialists. Using BitDefender seems to be tantamount to having your inexperienced doctor repeatedly checking your specialist’s diagnoses on a regular basis…:-)….!

  • Jimbo

    This ‘Cloud’ technology is pretty awesome. I installed the FF add-on but never saw a way to download it.
    I have bookmarked their site and yes, it’s very fast.

    I used Panda Cloud Antivirus (which I am told can be used with other AV programs. I never had any conflicts and it found stuff my AV at the time never caught.

    Thanks for the article!!

  • acr

    I used this extension which was available for the Chrome browser. It’s pretty nice and fast. But I went back to Hitman Pro as it includes Gdata which has Bitdefender and Avast. HMP also has several other scanners as well and does a scan pretty fast.

  • Ashraf

    @Jyo: Hey, hey, hey looks like someone has done their reading. ;-)

  • Jyo

    @janetb: One thing I learned, firsthand, about antivirus programs is that they never catch everything. I’ve been infected once before while using Avira, so it does not make you invincible. Although I was really pissed off for a while, and even almost ditched Avira, I came to accept the fact that Avira isn’t perfect. The best you can do is have a good layered line of defense, and I include Avira in that lineup for its high detection rates.

    So I guess you could use this as a second line of defense, but I usually just stick to SpywareBlaster and Malwarebytes (my supplementary lineup). Oh and WinPatrol is terrific too.

  • Ashraf

    @rodken: BitDefender is definitely one of the best; AV-Comparatives results show it being at the top.

  • rodken

    Some may disagree with me, but I consider BitDefender to be the more world-reknowned specialist than Avira (Free).
    Have used this for a while now and it is extremely fast, hasn’t caught anything though so can’t say how good it is. Their offline antivirus is great though. Avira has way too many false positives.

  • Ashraf

    @MikeR: Either you have a lot of RAM/startup programs – and I mean a lot – or there is something wrong. There is no way it should be taking you over an hour even if you are on a slow Internet connection because

    1) Most of the scan is done locally. The only time your Internet connection comes into play is when sending the hash list or uploading files, which should be near the end of the scan (at 90%).
    2) Unless you have a lot of programs BitDefender does not recognize, there is minimal data exchange between you and BitDefender servers (less than 1 MB). So even with a very slow connection it shouldn’t take very long.

    Have you tried it on a different computer?

  • MikeR

    Nice find, Ashraf. Well. I think so. Although there’s no elapsed time counter on the BitDefender scan, I can confirm it has just reached 86% of the scan after 1 hour 12 minutes. . . I have a slow ADSL connection so maybe that accounts for it. Either way, lilghtning — in my case — is, er, faster. ;-)

  • Ashraf

    @janetb: Honestly? Probably not. But hey, layered defense… remember?

    @Baconwallah: You are welcome!

    @David Roper: Ditto. Sort of, anyway.

    @charless: I don’t think Janet was asking if BitDefender had good detection ratings or not. I believe she was asking if Avira would miss anything that BitDefender would find. Since Avira has very high detection ratings, I doubt it.

    @janetb: Personally, yes I would welcome any second opinion by anyway if the problem was life threatening or very serious.

    @Troll: Same here. Having a fresh pair of eyes almost never hurts as long as you realize the limitations of the fresh pair of eyes.

    @Rob (Down Under): You are welcome. And I swear I am not doing anything to the tickbox; it has a mind of its own LOL! My Guess is the “tick status” is stored in dotTech’s cookie in your browser.

  • Rob (Down Under)

    I am a lazy B regarding protection.
    I have Avast free.
    I have NoScript (FF extension)
    I have nothing else.

    Tried running it from the web site.
    The button disappeared, and nothing seemed to happen.
    I downloaded the FF extension version.
    That ran pretty quick
    Found three programs that it wanted to upload,
    I declined, as they are programs that I wrote (eg Capslock Warning)
    It completed, and advised no Viruses.

    Thanks Ashraf

    PS I see the checkbox was pre-ticked
    Thanks again.

  • Troll

    @janetb: Given the fact that even experienced doctors fail from time to time, I wouldn’t mind getting a second opinion from an inexperienced one, if it felt like the right thing to do at the time. :) I have no experience with neither Avira nor BitDefender, though.

  • charless


    I have used BitDefender in the past and will continue to do so. My F-Secure has missed one or two over the years.

  • janetb

    @David Roper:

    I see your point, but it fails to answer my question….:-)….

    If you had thorough testing and examinations by a world-reknowned specialist in the field of your disease, do you really think having a quick look-over by a doctor just out of medical school is going to add anything significant? I’m prepared to accept a ‘Yes’ answer, but an explanation would be in order….:-)….

  • David Roper

    @janetb: Janet, from the write up: The point of BitDefender QuickScan is to conduct quick, on-the-fly scans that provide a second opinion as to if your computer is infected or not.

    It’s second opinion, like going to two doctors just in case the first one missed something. The reason we don’t do that much is that it costs so much to go to two doctors. But this “check up second opinion” is free.

    My advice: Get it. Use it after a healthy day of surfing.

  • Baconwallah

    Very fast and – because of the server referencing – probably very few false positives or none at all. As a second opinion this is invaluable. Thanks for publishing this, Ashraf!

  • janetb

    Avira (free) has always let me know as soon as anything suspicious tries to enter my system. Do you really think that Avira might miss something that this little program will catch??