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Super UserFree antivirus solutions for Windows
[+132] [32] kristof
[2009-04-30 10:27:25]
[ windows software-rec anti-virus freeware ]
[ http://superuser.com/questions/2]

What free antivirus solutions would you recommend?

As mentioned by Tony [1], most of the free solutions are limited to personal use so the question will mainly focus on solutions for personal use.

See if your antivirus of choice is already listed. Chances are it is.

If you spot an answer that mentions one you already use, vote that up if you think it's a good solution.

If you know of a feature or drawback not listed, or can include experiences in dealing with it, please edit the answer accordingly.

If you know of any that can also be used at work please point this out.

This covers all Windows platforms from XP, Vista and Windows 7. If you see an existing entry that needs an update or to add your testimonial, please do.

(16) I was almost tempted to answer "Linux" :-P (I've been reading one of the SO joke threads for an hour) - David Zaslavsky
(8) Unfortunately the answers to this question will eventually expire. I hope we all come back to it and update our responses at that point. - Joe Philllips
(3) I have found this site to be useful in deciding on which software to choose, just my two cents: av-comparatives.org - Josh
@Josh That's not just your 2 cents. AV-Comparatives are the testers. - muntoo
[+139] [2009-10-13 18:05:29] kajdehoop

Microsoft Security Essentials [1]

Limited to personal or home-office use and small business up to 10 PCs only. Requires genuine Windows.

Features

  • No registration, no ads
  • Simple, unobtrusive UI
  • Updates via Microsoft Update (note: virus definitions are updated more often)

Now extremely widely used and well tested!

[1] http://www.microsoft.com/security_essentials/

(1) I've actually heard that MSE is terrible at catching malware compared to the popular antivirus solutions. Don't know how true this is though. - musicfreak
(3) So far, that's not been my experience. I started using it when it was released to the general public. I check my computer with Malabytes, also. The only difference is that Malabytes flagged as a problem, the fact that I hadn't set Microsoft update for automatic updates (not really worthy of being flagged).. - Xavierjazz
Handy for work, as most other free ones have a 'personal/home use only' condition - MGOwen
@MGOwen: Very, very unfortunately not. From the EULA of MSE: "You may install and use any number of copies of the software on your devices in your household for use by people who reside there or for use in your home-based small business." - Ilari Kajaste
(2) they detect C code that contains exploits as a virus. And as a non-admin user you cannot even block it from moving half of your milworm archive into the quarantine folder... (Fortunately, you can log in as admin, add an exception and manually move all that "viruses" back to where they belong). - mihi
(7) This is easily the best free product out there. I previously used AVG and F-Prot, but they kept trying to upsell me, and required regular maintenance to keep updated. Microsoft just integrates smoothly with the automatic upgrades, and just works. @mihi; technically, if you're downloading what-might-be-a-virus from an exploits database... I'd be glad that it catches it! - Dean J
It is my understanding that MSE does not do any email virus scanning. For advanced users that's not likely a problem but I wouldn't use it on grandma's computer. - Steve Hiner
(6) @mihi: Frankly, I doubt the normal computer user has an archive of exploit code lying around. You can still put it in an encrypted archive if you don't want something to catch it. - Joey
(3) @Ilari Kajaste The EULA has now been changed to allow small businesses: Small Business. If you operate a small business, then you may install and use the software on up to ten (10) devices in your business. Restrictions. The software may not be used on a device running an enterprise version of a Microsoft Windows operating system. The software may not be used on devices owned by government or academic institutions. - Colin Pickard
@Colin Pickard Thanks for the update! - Ilari Kajaste
+1; I've switched to it on all my Windows boxes. Caveats: a) the installer will enable the Windows Firewall by default, although you can disable that during install; b) the installer will enable full Autoupdate, so if you don't want that, change it immediately after installing. - boot13
The link in that answer is dead, use this one instead: microsoft.com/security/pc-security/mse.aspx - Fueled
1
[+57] [2009-04-30 10:29:18] Blorgbeard

avast! Free Antivirus [1]

Free for home use only.

Features

  • Very Fast [2]
  • Very small, fast updates (highly recommended for those on dial up)
  • Lightweight [3]
  • Updates released really often (if it is needed, immediately)
  • Boot-time scans
  • Voice notifications
  • No ads

Drawbacks

  • Frequent audio/popup notifications may be annoying. (Can be disabled)
  • Email registration required. (They haven't to date abused this, though.)
  • Bundled software (Google Chrome; optional during install.)

Other

[1] http://www.avast.com/en-eu/free-antivirus-download
[2] http://av-comparatives.org/images/stories/test/performance/performance_dec_2010.pdf
[3] http://i278.photobucket.com/albums/kk112/takerraj_photos/memoryusage.png
[4] http://www.avast.com/audio

yes, I use this too. but I'm not going to upvote someone just because they use the same AV as me :) - community_owned
Fair enough too - this should probably be a community wiki question - community_owned
Good point, I have changed the question and my answer to wiki - community_owned
I have Followed suite - community_owned
(1) -1, only because I'm simply positive that software only finds false positives and trys to SCARE you into thinking it does something productive. - community_owned
(8) If you can, turn off the updating sound as well. There's nothing more annoying than having your speakers plugged in and on loud and having a robotic voice scream "Your virus database has been updated" at you. - community_owned
I'm an Avast fan as well, although I would recommend skinning the UI. I find the default skin pretty heinous. I use this skin - avast.com/eng/avist-avast-skin.html - whatknott
(49) I would put "skinnable UI" in the "drawbacks" column... - JesperE
(23) Why would anyone want to "skin" their anti-virus program? - DisgruntledGoat
(2) The avast! sounds can be turned off using the Windows sound management; avast! hooks into that. - Daniel
(6) If a skinnable UI is the only feature you can think of, doesn't that say something about the software? ;) - musicfreak
"Skinnable UI" Great example for Bug is a feature - CodingTales
(6) Skins are what software developers build when they can't think of real features to add. - Joel Coehoorn
(1) It slows down system, also slows down internet download. - Ismail
Why is "Skinnable UI" in both features and drawbacks? - muntoo
I love AVast, I used it for the longest time. However, lately I've been recommending MS Security Essentials to friends instead because MS SE doesn't require a separate e-mail activation every 14 months. That's a huge difference in terms of actually getting people to keep the software up to date over time. - Joel Coehoorn
muntoo: Because it's nice to see, but uses more resources. It's sort of "neutral". Also: It's true that when programmers can't think of something they start putting in useless features. Like me implementing a web-texture-loader into an XNA game. - sinni800
Avast used to be great, but is now bloated with junk, and the continual need for re-registration is ridiculous. - UpTheCreek
2
[+46] [2009-04-30 10:40:00] tharkun

Avira AntiVir Personal [1]

Limited to personal use.

Features

  • No registration required
  • Unobtrusive and reliable
  • Good customer support
  • Regular updates

Drawbacks

  • Displays/nags ads after each update of the virus definitions

Extras

  • Kill the ad nagging by adding a software restriction for avnotify.exe
[1] http://www.free-av.com/

AntiVir is quite performant (from a detection point of view), however (the free version) has a tendency to display quite a lot of "buy me" ads (at every update AFAIK) - community_owned
This can be helped by adding a software restriction policy for "avnotify.exe". - community_owned
I find Avira to be the fastest (least impact). It's very low load. - IDisposable
(2) Another good thing about Avira is their customer support. Just recently, Punk Buster triggered a virus warning, so I went to their site, sent their team a copy of the file, and then within a one or two updates, I stopped getting notifications about the Punk Buster files. - Thomas Owens
Avira is my current favorite. I installed it on an older netbook with only 8GB of hard drive space and it is very reliable, the only drawback is the occasional ads you see on the free version. - Heather
I have had a bunch of computers get infected while running up-to-date Avira. I use AVAST now for the free antivirus needs. - ssvarc
(2) I wouldn't say "unobtrusive" due to the ads they show, but it's easy to work around so +1 nonetheless. - musicfreak
(1) It tends to have a quite a high false positive rate (aggressive heuristics) especially with graphics demos or entries for sizecoding competitions (as they use unusual API/opcodes to stay small and/or use EXE packers), but I don't know any free alternative that is better here. - mihi
This is the AV to use in 2010! Long live Avira, its the new AVG - JL
3
[+44] [2009-04-30 10:53:04] Tony Meyer

AVG [1]

With regards to the second part of the question:

Limitations:

  • Support. You're unlikely to get support from the provider, and if you do, it's likely to be of lower quality (e.g. slower) than for a paid product. For most users, I doubt support for anti-virus software is that important, but some people like to have a number to call for everything.
  • Usage restrictions. Most free solutions are limited to personal use only. For example, AVG's free edition is limited to "private, non-commercial" use only, which means you can't (legally) use it on your work computer, even if you're a small business.
  • Functionality. Often free versions have more limited functionality. Using AVG as an example again, their paid versions have IM, identify theft, spam, and rootkit protection, and a firewall.
  • Ads. Often a free product will incorporate some form of advertising (even if it's just for a paid version of the same product). This can range from a subtle image in the UI (which you'll rarely use), to something annoying.

As for dangers, I presume you mean "are these products less likely to catch viruses?". Perhaps. You can look at evaluations (e.g. the Virus Bulletin ones [2]), although some people argue that those aren't particularly meaningful. In my experience, if you keep whatever product you use up-to-date (and the definitions up-to-date as well), and you have a firewall, and you're behind some sort of NAT (e.g. most home connections), and you keep your OS up-to-date, and you don't behave stupidly, then you have little risk.

FWIW, despite these limitations, I always recommend free anti-virus to friends/family (typically AVG). For the commercial situation, there are many advantages in the commercial products, but there are plenty of good free choices for personal, home, use.

[1] http://free.grisoft.com
[2] http://www.virusbtn.com/vb100/archive/results?display=summary

(1) Thanks Tony, that is a great answer. I actually do same recommendations as yours for family/friends. Also as most of the free solutions would be limited to personal use, I should probably update the question to reflect this - community_owned
I use AVG myself and like it a lot because of it's low footprint and resource use. Previously I have used Norton Antivirus, for example, which was a huge resource hog. - Stefan Thyberg
(30) The recent AVG versions are a total resource hog. - DisgruntledGoat
(2) but which antivirus is not a resource hog? - Decio Lira
AVG works great on all of my home systems except an older XP machine, which was brought to its knees by avg - had to switch that one to avast. - Traingamer
(2) I was very much a fan of AVG, but twice in the last few months my wife managed to infect her computer with something bad while running AVG (yes, up-to-date database). At the moment, I am exploring new options - pending towards Avast at the moment. - Wilson
(1) I've had similar experiences as Wilson. AVG used to be good but now it tends to suck. - Joe Philllips
(1) I've been cleaning up my PC in the last couple days of dozens of nasty items that got onto it despite the fact that I was running AVG with a daily scan. I am NOT happy. - Kyralessa
I won't defend the resource hog issue. It seems every A/V goes through a poor performance release every few years. Now it's AVG's turn. I will say this about getting infected while running any brand of A/V- it happens to ALL of them. By "ALL of them", I mean, I've seen infections on ALL of them, every brand, even with up-to-date db's. - kmarsh
(4) i dumped AVG when it added the pre link checker thingy for web surfing. Right pain in the $%* and slowed systems down. I'll vote for Avira when I find its answer - ianfuture
No more AVG for me either. Dumped and dusted. - JL
(2) Every six months AVG tries to upsell by releasing a new version and trying to get you to pay for it. You then have to go through the download and reinstall process to continue getting virus database updates. Although there is always a free version available it asks about 10 times whether you want to buy the premium edition or not. Lame. - codeulike
(1) I recently switched to a provider with high upstream bandwidth (50mb/s upstream), and seeding anything popular totally bogged down my computer (already at speeds above 100kb/s). Turns out AVG was the culprit, just uninstalled it and currently seeding at 600kb/s with almost no cpu usage. Also, it's "identity protection" service bogged down Synergy+ in the same way anytime my mouse was on the other screen. Would not 'buy' again. - Sverre Rabbelier
AVG is crap. The number of installations I've seen that wouldn't update is astonishing, and I've seen a few that wouldn't even let you uninstall it. It also fails miserably at actually detecting malware. It'll get it if the bug is years old and well known, but you can forget about anything else. - Matthew Read
4
[+23] [2009-04-30 11:33:30] Guy C

ClamWin [1]

An open source product.

Features

  • Database updates pretty fast with new virus definitions
  • Outlook plug-in allows you to scan incoming and outgoing emails

  • Can be set to work with Firefox to scan downloads with a Download Statusbar add-on. Add-on has to call ClamWin.exe on the command line with the following:

    "--mode=scanner --remove --close --path=%1"

    which will remove any flagged and closes after each download

Drawbacks

[1] http://www.clamwin.com/
[2] http://www.clamwin.com/content/view/35/27/

(2) You can scan after download with FireFox by using the Download Statusbar addon, and tell it to call run ClamWin.exe with the command line "--mode=scanner --remove --close --path=%1" to auto remove anything found and close after the scan for each file downloaded. - community_owned
+1 Clam antivirus is used to scan emails, so I trust it's virus database. - Mercer Traieste
+1 Clam is great espeially as its open source. - Mark Davidson
(1) No real-time scanning defeats the purpose of having an AV for me. - musicfreak
(1) An AV purpose is to secure you, but when your stuff is secure why scan it all when you just can scan the new stuff that you add to your computer ??? that's why clamwin could be decent for most peoples if they take the time to configure it a little ... - zillion
(1) musicfreak: What is the point of having AV if it hogs resources with resident scanning. Resident scanning is such overkill, it is like having a virus running all the time. Claimwin let's you scan memory, which is as good as resident scanning. - Zombies
Clam Sentinel can be used to provide on-access scanning. - Xenoactive
5
[+22] [2009-07-15 07:13:00] Kevin Babcock

Antivirus software? Never! I just keep images of my system in a fresh state and backups of my data. Reload the system every 3-6 months to keep it fresh and snappy.

But if you must use AV software, I recommend Kaspersky or AVG.


(15) Second the "none" option. Practice safe and secure computer usage and you don't need to worry about viruses because you won't get them. - jtimberman
(9) -1 I wouldn't ever think of a pc without AV, specially if I'm running Windows. - Galilyou
(7) @7alwagy that's nice to know, but i've been running without AV for years and I haven't had any problems. I use free online scanners every few weeks and nothing is ever found. Keep up to date on your patches and don't download suspicious things and you'll be fine. Last time i got a virus (about 9 years ago, when i HAD antivirus), the AV program I had didn't stop the virus, and it couldn't clean it from my machine! What value do these things actually deliver? A false sense of security is all. - TM
While there are viruses that don't require the user to do anything (i.e. they infect your machine by brute force port scanning) these rely on security holes that have had fixes available for months or even years. Sadly, I've seen time and time again Windows machines with the automatic updates turned off still running the version that came preinstalled. These same machines are usually filled with every worthless app the user stumbled across on the web. Being a software packrat myself, I at least have enough sense to try out new apps in a VM where I can just rollback if it turns out to be crap. - Kenneth Cochran
(2) After reading this post codinghorror.com/blog/archives/000929.html, I uninstalled my AV, and I never seen a virus in my PC ever since. - ianix
(1) "Culture of Fear" ir right. the so-called IT security industry one giant protection money racket. :) - community_owned
@Kevin, curious how you restore the plethora of configs at your periodic image resets? There are so many facets, and they keep evolving over time: app settings, etc. I try to backup all the various nooks and crannies, but reapplying everything is a multi-day effort. - Chris Noe
(1) I use Windows Home Server. I take incremental backups during the build process and then let WHS take nightly backup images of my entire HDD. Then whenever I feel like the machine has become too bloated, I reload whatever image I'm most comfortable with. As with any system reload, there will always be some manual effort involved to reconfigure things...I just try to keep it at a minimum. - Kevin Babcock
@7alwagy - Running without A/V for years, never had a problem since Windows XP RTM and Blaster. - todda.speot.is
@Kevin, remember to add (and use a router) no point in directly connecting to a DSL connection using a modem, without AV. - JL
I agree wholeheartedly - I've not run antivirus software since I've started using computers (about 15-18 years ago) and I can count the times I've had viruses on one hand. But I'll note, the frequency of unintentional - altCognito
(6) -1 for suggesting to run without AV - Iszi
(3) By the time you know that you have a virus, there is potential that your data has already been stolen. Recommending that users not use an AV at all is incredibly irresponsible. - MarkM
(1) I wouldn't run an Antivirus on my machine, but I would never set up a machine for a non-expert user without one (e.g. parent, grandparent, brother etc. which I always seem to end up doing) - rjmunro
(11) -1 How would you know you have malware without looking for it? Trojans just hide and steal your data; they don't say: "Hey! I'm stealing your credit card information! Do you want to install some antivirus software? I recommend AVG or Kaspersky!" - muntoo
Without running antivirus you're sure to not know you have one!!! So you feel secure. Relying on an online antivirus is a joke in my opinion as antivirus are used to protect exactly from online threats because you don't know if sites are reliable... - laurent
You'd think this is true until one of your trusted sources gets hacked, or you run into a nasty trojan that gets through your firewall (assuming you have that). Why bother with the hassles of constant restores if you don't need to? Practice appropriate computer usage and your system won't randomly become "stale" or not snappy. There are good solutions with a small footprint, so if someone is really worried about that they might want to consider upgrading from 90s hardware. - Matthew Read
6
[+10] [2009-04-30 10:38:37] Ionel Bratianu

Comodo [1]

Current free version edition combines the antivirus and firewall. You can opt out of either component if you're already using or want to use another vendor.

Features

  • Can be set up to constantly nag you about programs trying to access the Internet without explicit permission
  • Also has one of the best free firewalls as option to install with
  • Set up zones outlining what software is allowed to access what of the computer, registry and memory, etc.

Drawbacks

Supported systems

  • Windows XP (SP2) - 32 and 64 bit versions
  • Windows Vista/7 - 32 and 64 bit versions
[1] http://www.comodo.com
[2] http://news.softpedia.com/news/Comodo-Software-Removed-From-Softpedia-110169.shtml
[3] http://forums.comodo.com/other_general_gui_etc_bugs/cmdagentexe_hogging_cpu-t46124.0.html

This one just sounds fishy to me. - scheibk
@scheibk: It's legit, I used it for about a year and a half before switching to Nod32. My only complaint is that the "Defense+" feature is over-aggressive and resulted in a lot of false positives for me. - musicfreak
I started with their firewall, and when they released the antivirus, decided to try it. So far, I've really liked it. While the virus scanner does miss things (they all do), the "Defense+" function has managed to prevent the few viruses I've had from getting a toehold on my computer. Once you take the time to train it to what you have installed, it's quite good at catching things that shouldn't be happening. The firewall is also AMAZINGLY configurable. You can setup access rules for IP/IP Range/Protocol/Port for each application. - Fake Name
It's currently the best proactive solution according to Matousec. - Greg
I don't like the firewall configuration. The Defense+ sucks even more when you use cygwin, it slows some things down not by 10% but by a factor of 10. Killing the cmdagent.exe is the only way allowing me to do git rebase without spending hours with it. In other respects, it's fine. - maaartinus
+1. I don't like Defense+ either, but Comodo is simply the best firewall (change the configuration if you dislike it) and their antivirus is well-integrated and much better than cheap crap like AVG. - Matthew Read
7
[+6] [2010-02-20 20:13:21] fluxtendu

Malwarebytes' Anti-Malware [1]

An anti-malware application that can thoroughly remove even the most advanced malware.

The free version doesn't have real time protection but it's a good alternative to make complementary on-demand scans.

[1] http://www.malwarebytes.org/mbam.php

8
[+5] [2010-02-20 19:02:24] Goyuix

VirusTotal.com

[1]

VirusTotal is a service that analyzes suspicious files and facilitates the quick detection of viruses, worms, trojans, and all kinds of malware detected by antivirus engines.

VirusTotal Uploader [2] enables you to directly send files from your system using the context menu.

Specs:

  • Free, independent service
  • Use of multiple antivirus engines
  • Real-time automatic updates of virus signatures
  • Detailed results from each antivirus engine
  • Real time global statistics

Pros:

  • Web Based
  • Scans files using free/open/commercial scanning engines
  • compares results
  • Lists a bunch of other interesting properties about the files

Cons

  • Web based
  • Single file upload
  • Potential size restrictions
[1] http://www.virustotal.com/
[2] http://www.virustotal.com/metodos.html

Virustotal has a 20 mb filesize max. I use the uploader a lot, but you do have to be aware of the limitations. - Fake Name
The best thing about VirusTotal as opposed to Jotti, virus.org, and the others is that VirusTotal caches the hashes (yes, yes, very funny). So if you use the uploader, you it hashes your file and checks to see if it already has a scan on the file. That way you can avoid uploading the file at all, thus saving you bandwidth, and allowing their service to run so much more efficiently and not overloaded. (Of course you still have the option of forcing an upload, say if the existing scan results are from a few years ago, using old DATs.) - Synetech inc.
9
[+5] [2009-04-30 13:05:35] Nick Berardi

Panda Cloud Antivirus [1]

The first antivirus based on this innovative protection model which is based on two fundamental principles:

  1. Automatic malware detection and remediation from the cloud in real-time.
  2. The use of an ultra-lightweight thin-client agent that off-loads the hard work to the server
[1] http://www.cloudantivirus.com/

I've been using a Mix of Panda Cloud and ClamWin... - community_owned
(3) Panda misses a lot of samples - Casey
Go Panda! I use it in combo with some other stuff. Just added. Light-weight, but wicked fast and powerful. - The Green Frog
(1) You forgot the biggest drawback of Panda Cloud: it automatically deletes anything and everything it so much as thinks is bad without giving you any sort of prompt or undo functionality! - Synetech inc.
10
[+4] [2009-07-08 20:45:00] Kev

Dr. Web CureIt! [1]

Not a true resident antivirus suite but it's good tool to make an on-demand scan.

There's also a Live CD [2] version that could be useful

Features

  • No install required, comes as a self-contained EXE

Drawbacks

  • Nagware
[1] http://www.freedrweb.com/cureit/
[2] http://www.freedrweb.com/livecd/

11
[+3] [2009-04-30 11:59:17] Scott and the Dev Team

HouseCall [1]

From Trend Micro

Features

  • Web based

Drawbacks

  • Web based
[1] http://housecall.trendmicro.com/

12
[+3] [2010-02-20 18:51:46] fluxtendu

Kaspersky Virus Removal Tool [1]

Not a true resident antivirus suite but it's one of the best tool to make an on-demand scan.

Kaspersky® Virus Removal Tool is an utility designed to remove all types of infections from your computer. Kaspersky Virus Removal Tool implies effective algorithms of detection used by Kaspersky Anti-Virus [2] and AVZ [3].

Kaspersky Virus Removal Tool is not capable for real-time protection of your computer. As soon as your computer is cleaned you are supposed to remove the tool and install a full version of antivirus software.

Highlights

  • Easy interface.
  • Can be installed to an infected machine (Safe Mode supported).
  • Integral search and removal of malicious software: effective combination of signature detection and heuristic analyzer.
  • System Analysis and interactive scripting language.

Basic functions

  • Automatic and manual removal of viruses, Trojans and worms.
  • Automatic and manual removal of Spyware and Adware modules.
  • Automatic and manual removal of all types of rootkits.
Known issues:
  • System memory is not available in x64 OSes Windows XP / Vista / 7 because of work specifications of the application's system drives.
  • if User Account Control is enabled in Windows Vista settings, then it is impossible to rename a folder with application's files if Self-Defence is disabled.
[1] http://devbuilds.kaspersky-labs.com/devbuilds/AVPTool/
[2] http://www.kaspersky.com/kaspersky_anti-virus
[3] http://z-oleg.com/secur/avz/

13
[+2] [2009-07-15 07:16:39] IDisposable

I'm quite happy with Avira AntiVir [1] free for all of the home systems I have to administer. Lately, I'm personally running the new Microsoft Security Essentials [2]. It's VERY low load and updates several times a day.

[1] http://free-av.com
[2] https://connect.microsoft.com/securityessentials

+1 for Microsoft Security Essentials. - AndyMcKenna
(1) Already posted: superuser.com/questions/2/free-antivirus-solutions-for-windows/…; superuser.com/questions/2/free-antivirus-solutions-for-windows/… - Hello71
(1) Yes, months later - IDisposable
14
[+2] [2009-04-30 11:54:40] Nate

I've always been intrigued with Threatfire [1]. I've installed it on a couple virtual machines but rarely encounter viruses in my daily life so I am not sure how effective a solution it is.

[1] http://www.threatfire.com/

Unlike you, I deal with malware every day literally and I have to say that Threatfire is super effective, especially the new version 4.5. - Casey
It's not properly an antivirus, it's a HIPS. It's a good complemental solution - fluxtendu
Threatfire closed my (>50) open tabs in Opera whenever I closed Opera. After uninstalling threatfire they remained open again. Which was painful as I tend to keep sites worth reading open (sometimes for weeks/months until I find time) instead of bookmarking them (and deleting the bookmark later). - mihi
15
[+1] [2009-05-01 22:39:25] Avery Payne

AntiVir [1] out of Germany. Updates are very regular and detection has been very good. Yes, the free version is limited to personal use. The only drawback is when it updates, a nagware screen shows with an OK button. Just click [Ok].

[1] http://www.free-av.com/

you mean Avira AntiVir see one of the answers above with more votes that also recommends this. Perhaps remove/merge this with that answer? - ianfuture
My answer was on May 1, that answer was in July, two months later. Happens sometimes. :) - Avery Payne
16
[+1] [2010-02-20 19:08:54] mihi

PrevX [1]

Although not a complete antivirus product (I use it in addition to Avira)

Features

  • Scans a system very quickly
  • produces good results even when running it on an infected system (thanks to the rootkit detector)
  • can scan a system where another antivirus product is installed
  • tends to detect some exotic malware that is not found by Avira/Avast

Drawbacks

  • Will not find malware in every file, but only in places where the real malware will copy itself to. I.e. it is not sufficient for scanning your backups.
  • Cannot disinfect the system (unless you can just delete the files manually)
[1] http://www.prevx.com/

PrevX is one of those AVs that I have heard about for years. Recently I tried it and was really irritated because the keyboard hook it installed caused a lot of trouble. I ended up having to use their removal tool to completely get it off of my system since simply disabling/uninstalling the keyboard-logger protection did not suffice. - Synetech inc.
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[0] [2010-09-29 13:20:43] greuze

The best free antivirus I ever used is Avira Antivir ( http://www.antivir.es/cms/ ), the virus found ratio is much better than AVG or Avast.


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[0] [2010-11-09 23:30:26] Pat

Secunia PSI [1]

It's not an antivirus, per se, but it's fantastic software for seeing what apps on your machine are vulnerable and thus preventing viruses from having an attack point.

What I particularly love about it is that there is a Simple and an Advanced interface. The simple interface makes it easy for non-tech users to just click to fix. In both interfaces, it's easy to click to go directly to the download of whatever software needs updating (which is very, very convenient).

Consider it!

[1] http://secunia.com/vulnerability_scanning/personal/

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[0] [2010-11-23 20:17:39] Oddy

I personally use ZenOK Free Antivirus its not just an AV it also antispyware, anti-spyware, ultra-light scanning, boot-up Protection a combined made a complete security suite protection.


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[0] [2009-08-25 17:21:08] community_owned

A-squared Commandline Scanner [1] for me, like ClamAv/ClamWin no on-access protection. despite using a dual scan engine (Ikarus) for Viruses and Malware/Spyware it is probably the fastest virus scanner there is. extraordinary high detection rate [2].

free for personal use.

[1] http://www.emsisoft.com/en/software/cmd/
[2] http://www.virusbtn.com/news/2008/09%5F02

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[0] [2011-06-28 22:58:47] Peter Maxwell

Spyware Terminator [1]

I use this on all of my computers and it works very well. It's free for personal and commercial use. It integrates with ClamAV, and is not very resource consuming either.

[1] http://www.spywareterminator.com/

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[0] [2009-05-08 21:29:29] nedm

At work, we experimented with Malwarebytes, ClamWin, and Comodo, but ultimately the first 2 don't do real-time scanning and Comodo's AV was too rife with false positives, and isn't windows certified, so it won't turn off the security-center AV nag, though it can be disabled by GPO (in Comodo's defense, their free firewall continues to be great). As a result, we shelled out for a commercial anti-malware suite.

If I had to use only free products at work, I'd install Comodo and SpybotS&D/TeaTimer, scan regularly with ClamWin and/or Malwarebytes, use OpenDNS, and keep my fingers crossed.


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[0] [2009-07-15 07:19:08] bhen

Sometimes local viruses doesn't get detected by software like AVG or AntiVir, for those who lived in Indonesia PCMAV [1] seems to be a free but works solution.

[1] http://pcmav.biz/download

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[0] [2009-04-30 11:19:18] Morph

I switched from Avast to Antivir, seems to be a bit more slim No registration needed so no key that expires, not quite sure if it catches more, as I don't come across many virii.

There is also Comodo BOclean [1], which is anti-malware, and seems to do it's business quietly.

[1] http://www.comodo.com/boclean/boclean.html

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[-2] [2009-04-30 10:28:25] kristof

I personally use AVG Free [1] combined with Spyware Doctor which is included in Google Pack [2]

[1] http://free.avg.com/
[2] http://pack.google.com/intl/en/pack%5Finstaller.html

(5) I agree, but lately AVG is pushing too far into tricking users to buy their paid product. Almost evil. - community_owned
Me too - I know they have to make a buck, but the assault course you have to negotiate to download AVG Free is getting ridiculous. - community_owned
(2) @Eduardo,Duncan - That is saddly true, it seems that they make it almost impossible for non technical user to upgrade to a new free version. If I remember correctly when the version 7 started dispalying massage "Upgrade to version 8" I had to google for free avg 8 version, as the free version 7 installed was directing to the full version and there was no links on the page for the free one. - community_owned
Agreed on all counts. As long as you know that the free version is still there you can find it - but you sure won't stumble across it anymore. - community_owned
(1) I wish Spyware Doctor had a 64-bit version. - community_owned
Post version 8, I've also been having increasingly severe disk I/O performance problems on my systems using AVG. I suspect it's getting heavier as well as more obnoxious… - community_owned
+1 for AVG, but for personal use your ISP may also provide a good (for free) security suite. For example Cox offers a suite of McAfee security products: ww2.cox.com/residential/sandiego/internet/… - community_owned
I've been using AVG Free for a number of years but am getting more and more peeved off by the number of false positives. Even some of my own software gets "detected" as a virus. - community_owned
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[-2] [2009-04-30 10:33:07] Shard

As kristof said AVG free is a good choice and also i would highly recommend spy-bot search and destroy [1] (Don't be afraid of the terrible site design :) )

[1] http://www.safer-networking.org

If you haven't used it, you might be surprised what Spybot uncovers when you think you've always practiced safe computing. - community_owned
(4) Most of the things "uncovered" by Spybot are cookies, which are not as big of threat as everybody thinks. - community_owned
(1) Spybot has failed to detect some real malware for me which Malwarebyte's Anti-malware found without a problem... not sure what I was doing wrong - but I'm sure more interested in finding actual malware on client's misbehavingg computers and not a few hundred mostly harmless cookies ^^ - community_owned
SuperAntiSpyware is better. - Casey
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[-2] [2009-08-18 18:57:17] Gray

Over the course of a long computer support career I've used McAfee, Norton/Symantec and others briefly at work. I've moved to using only freeware solutions at home and have not had any problems. I've tested many - Avast, AVG, AntiVir, Clam and others. I typically use Acast as my freeware anti-virus of choice due to its reliability, effectiveness and ease of use. The only drawback is the need to register once a year (free). Overall for security on my home systems I've been using a combination of [Avast][1], [Threatfire][2], [Comodo][3] (firewall), [Dr. Web][4] in FireFox with occasional double-checks using [Spybot Search & Destroy][5] and Housecall online anti-virus. It's always a good idea to periodically double-check your solutions by rescanning with another solution. Over time some will catch things that others miss.

http://www.avast.com/eng/download-avast-home.html


I’m guessing that you meant Avast since I cannot find an Acast. :) - Synetech inc.
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[-2] [2009-05-11 06:51:37] username

Hmm. When I used XP, I liked F-Protect, but they seems to have amassed quite a lot of bloat lately. Most of the Windows people I know now use ESET's NOD32 [1].

http://www.consumersearch.com/antivirus-software

[1] http://www.eset.com/products/index.php

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[-2] [2010-03-01 01:19:46] Shane Burgess

I will also say that Microsoft Security Essentials is the best free antivirus out there today. Being a computer technician I have seen this program in action from finding viruses on the drive to stopping them from being installed and I am very happy with it.

It also has a low footprint on your system so it doesnt slow down your computer.


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[-3] [2011-03-08 02:47:20] muntoo

PC Tools Spyware Doctor with Antivirus [1]

Or the more expensive PC Tools Internet Security 2011 [2] ( PC World's review [3])

Commercial/Shareware, $39.99. Here's PC World's 2010 review for Spyware Doctor only [4]. ( "Full" version [5].)

Features

  • Easy to understand UI
  • Comes with ThreatFire [6]
  • In previous years, it had top real-time Malware detection rates, and was PC World's top editor's choice in Antivirus/Antimalware (in previous years, before Symantec bought it ;) Thankfully, they've decided to leave it alone, and not ruin "improve" it like their other products)
  • Heuristics!
  • Good Zero-Day Threat protection (or so they say)
  • Ability to set Sensitivity level on detected threats; High/Medium-High sensitivity for geeks, and Low to Medium sensitivity for idiots ... err ... "normal people"

Drawbacks

  • It may be the reason (5% sure) my system crashes once every two weeks on average, especially when I'm doing Power User/geeky stuff or when my system comes out of screensaver mode. (With "normal" everyday simple-user stuff, it's alright.)
[1] http://www.microsoft.com/security_essentials/
[2] http://www.pctools.com/internet-security/
[3] http://www.pcworld.com/article/214633/pc_tools_internet_security_2011.html
[4] http://www.pcworld.com/downloads/file/fid,24015/description.html
[5] http://www.pcadvisor.co.uk/downloads/index.cfm?categoryID=1727&itemID=24015
[6] http://www.threatfire.com/

(1) The question specifically asks for free options. - Joel Coehoorn
@Joel There is a free version. - muntoo
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[-3] [2010-02-20 20:46:24] Fake Name

VirtualBox [1]

While it's not a virus scanner per se, it it probably the best way to check if a suspicious file is indeed a virus.

I regularly come across files that are dubious at best, and the easiest way to absolutely tell if they're indeed malevolent is to simply run them. Running them in a VM prevents them from doing any damage, and you can simply roll-back the VM to a clean snapshot to remove the virus.

While it is a bit involved to get an OS up and running in a VM, now that I have it set up I find it tremendously useful for other things (It's a great way to keep stuff you use irregularly off your main OS).

[1] http://www.virtualbox.org/

Yup! I have a folder of suspicious files (that I rename to a custom file extension I made for suspicious files, whose default command is to open with a hex-editor). Now and then, I launch a clean VM and examine the aforementioned files. (Actually, I mainly use VMWare, but I have VirtualPC and VirtualBox ready to go as well.) - Synetech inc.
(2) Seems like a recipe for disaster: what if the dubious file does nothing unusual except set itself up to nuke your hard drive in 10 days? On the other hand, if you need to run a dubious file for the effects that it's supposed to have, this is a good way to do it, and snapshots make it very easy to do this. Though I can't think of a scenario in which you'd want to do such a thing legally. - intuited
@intuited - Well, if you run it on top of a good behavior analysis tool (like Comoto Defense+), you will see it set itself up to nuke your HD in 10 days (modify system files, modify registry, etc..). Also, how many viruses do that? I don't think I've heard of any that have that behavior since the 80s. It's not profitable, and people write viruses for money. - Fake Name
(3) -1 for not an antivirus solution - Iszi
@Iszi - Can you use it to understand file behavior and determine if file are malicious? Yes. What more do you want? - Fake Name
@FakeName - Oh, there's a long list of things I might want, which most of the other solutions listed do provide. Virtualizing a test-bed system does indeed offer protection of the host system from anything that happens within the guest, and allows some chance at insight into what any malware on the guest system will do. But it does little to actively or directly protect the host system from software running on itself. - Iszi
@Iszi - Virus Scanner != Active protection system! A virus scanner only detects viruses in files it is pointed at. Many virus scanners on the market also include proactive defenses, realtime scanning ability, and other things, but none of these are intrinsic to a virus scanner, merely add ons. - Fake Name
@FakeName - Your statement is accurate. However, the question did not ask for a "Virus Scanner" - it requested an "antivirus solution". For something to be an effective antivirus solution, or "to oppose, prevent, cure, alleviate, combat, or defend against" (as are the Merriam-Webster definitions of "anti-") viruses, it must be an active protection system. - Iszi
@Isizi - By that argument, many of the answers are invalid: VirusTotal, TrendMicro House Call, Dr. Web CureIt! Etc, Clam Win... - Fake Name
@Fake Name This makes no sense. The program may behave randomly and do nothing wrong while tested in the VM. It may come the day when your up to now well-behaved programs start to do their real job. - maaartinus
I've never seen or heard of anyone writing a virus to do this (except, perhaps spear-phising operations, and a virus scanner won't help much there anyways). The only time I have ever seen viruses in a valid file are the instances where the virus dropper also drops a valid installer, as well as the virus, and in that case, the virus is installed immediately. Basically, they repackage a pirated software installer to also install a virus. - Fake Name
Remember, viruses are written to make a profit, and once you have execution rights on a machine, any waiting around is useless from a profit standpoint. Virus writers don't care to bother with delayed execution, because the only people it would help fool are technically inclined types, who would probably notice the virus once it starts acting up anyways. There are easier targets. - Fake Name
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