When we looked at the beta of Microsoft Security Essentials in 2009, we were impressed with its clean, easy-to-use interface, but less so with its sluggish scan speed. This still holds true for Microsoft Security Essentials 1.0; alas, it hasn't kept pace with newer antivirus products when it comes to detecting malware. Updated December 8 2010.

Microsoft Security Essentials is well designed and easy to use. Installation is simple and straightforward, although it will verify whether your copy of Windows is legit along the way. Once you install it and open it, you'll be greeted by a thoughtfully designed main screen. This screen has four tabs: Home (which shows status information, scan controls, and an update button if your virus definitions are out of date); Update; History (which logs all of the malware cleaned from your system); and Settings.

Microsoft Security Essentials has a green/yellow/red colour-coded status bar that runs across the top of the window - as is common in antivirus software - and the Home tab gives you more details as to your PC's protection status.

While not terrible, Microsoft Security Essentials lagged behind the top performers in our recent antivirus roundup at detecting malware using traditional scanner-based detection methods (which rely predominantly on malware definition files), detecting 92.7 percent of samples. This was the second-lowest score of the free antivirus products (Comodo's free Internet Security Premium was slightly worse, detecting 92.4 percent of samples), and is well behind the top performers, which detected over 99 percent of malware samples.

Microsoft Security Essentials logged the lowest score in tests to see how well it could block real, live malware attacks. In these real-world attack tests, it completely blocked 64 percent of attacks, and partially blocked an additional 8 percent of attacks. No free antivirus product was able to fully block all attacks, but Comodo scored a 96 percent full-blocking rate. This is a good test to determine how well security products can block brand-new, still-unknown malware.

On the other hand, once an infection is on your PC, Microsoft Security Essentials will do a relatively good job at cleaning it up: It detected all infections on our test PC, and removed all active components of an infection 70 percent of the time - about average for the products we reviewed. And it managed to completely clean up 50 percent of infections - tops among the contenders.

Microsoft Security Essentials' scan speeds are among the slowest among products we looked at, as well. It completed our on-demand scan test - which simulates how long it will take to manually scan 4.5GB of data - in 3 minutes, 24 seconds, the second slowest performer in this test. The top performer, Avira Antivir Personal, completed the test in 87 seconds. Security Essentials was also on the slow side in on-access scan speed tests, which judge how well a product can scan files as they're opened or saved to disk: It did the deed in 5 minutes, 41 seconds, a full 2 minutes behind the leader.

Despite the slow scan speed, Microsoft Security Essentials had a fairly low impact on overall PC performance. It added less than 1 second to startup times in our tests, and finished most of our other system speed tests with better-than-average scores.

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Verdict

There's a lot to like about Microsoft Security Essentials, but we were a little disappointed by its malware detection and attack blocking - after all, antivirus software is only as good as its ability to keep your PC protected. Hopefully, Microsoft will bolster Security Essentials' threat-blocking capabilities in a future update, but until then, you'd be better served by going with something having better detection capabilities, such as Avira AntiVir Personal.

NEXT: our review of Microsoft Security Essentials, from 2009 >>

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An effective if somewhat slow utility, Microsoft Security Essentials is a solid contender in the free antivirus space. UPDATED WITH INDEPENDENT TESTS, October 1 2009.

Microsoft Security Essentials shows much promise. In our tests it was decent at detecting malware, particularly in proactive tests that simulate the handling of new, unknown malware. It took fourth place in our rankings of free antivirus software. The main drawback of the tool, due to launch on September 29, seemed to be its slow scan speed.

One thing we hope Microsoft will improve is Microsoft Security Essentials' relatively poky scan speed. It was the slowest in our on-access scan test, which judges how quickly scans run when you copy, open, or save files. The app's Dynamic Signature Service may account for some of that: When Security Essentials sees a potentially malicious file that doesn't match known malware, it contacts Microsoft servers for additional analysis. The feature likely affords greater protection owing to the use of the latest signatures online, but it may also introduce some delay if Security Essentials has to wait for a response.

See also: Is free antivirus software safe?

See also: Tutorial: Build a free, multilayered security setup

Microsoft Security Essentials' ability to detect and block malware was neither especially good nor particularly bad. Its 97.8 percent overall detection rate put it in fourth; but it did well in proactive tests, which use two- and four-week-old signature databases to simulate how well a program detects new, unknown malware. Its results of 52 percent and 43.8 percent, respectively, were second only to those of the top-ranked Avira Antivir Personal, our overall winner.

Microsoft Security Essentials slated by rivals

Microsoft Security Essentials put up no false positives (flagging of benign software), and it got a near-perfect score overall in detecting and cleaning rootkits and malware infections. It detected and disabled every infection, and although it left behind several changes to the Registry and other areas (as every free app did), they couldn't cause further harm.

NEXT: AV-Test.org's technical tests >>

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An effective if somewhat slow utility, Microsoft Security Essentials is a solid contender in the free antivirus space. UPDATED WITH INDEPENDENT TESTS, October 1 2009.

Microsoft Security Essentials: independent tests

Microsoft's free Security Essentials antivirus software identified 98 percent of over half a million malware samples, an accuracy rating an independent testing company calls "very good".

Germany-based AV-Test.org tested Security Essentials on Windows XP Service Pack 3 (SP3), Vista SP2 and the final code of Windows 7, against two different collections of malware, said Andreas Marx, one of the firm's two managers.

The first test put Security Essentials in the ring against more than 3,700 viruses, Trojans and worms culled from the most recent WildList, a collection of threats actively attacking computers. "All samples were successfully detected and blocked during our on-demand and on-access tests," Marx said.

The second test pitted Security Essentials against a much larger set of malware. Of the 545,3444 malware samples in that collection, Microsoft's software nailed 536,535, resulting in what Marx characterised as a "very good detection score" of 98.4 percent.

In a follow-up test of adware and spyware detection Microsoft's software spotted 12,935 out of 14,222 samples, for a 90.9% accuracy rate.

This is the second time that AV-Test.org has run Security Essentials through the mill; when Microsoft launched a limited preview in June, the group tested the beta. Then, the free software also breezed through the WildList, spotting every sample in the 3,200-plus set.

Security Essential's final version also successfully identified and deleted all 25 rootkits AV-Test.org threw against it, Marx said.

But there were some things that Microsoft's program had trouble handling. Most security software now includes an ability to sniff out malware by the way it behaves, often by using heuristics-based scanners that don't rely on specific 'fingerprint' signatures to match against a potential threat. Security Essentials lacks any such technology.

"We found no effective 'dynamic detection' features in place," Marx noted. "None of the samples were detected based on their suspicious behaviour. However, other antivirus-only offerings doesn't include dynamic detection features, either. In most cases they are only available in the internet security suite editions of the products."

Security Essentials was also able to completely scrub a PC when it did detect malware. "In many cases, traces of infection were left behind," said Marx, ticking off several examples, including empty 'Run' entries in the Windows registry and modified 'hosts' files. The program also failed to switch on the Windows firewall after a piece of malware had deliberately disabled it.

NEXT: our first look at Microsoft Security Essentials, from June 2009

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An effective if somewhat slow utility, Microsoft Security Essentials is a solid contender in the free antivirus space. UPDATED September 29 2009.

Microsoft Security Essentials - in detail

From June 2009.

The just-released beta of Microsoft Security Essentials - not yet available in the UK - is a solid, free tool that protects against malware while taking up few system resources and staying out of your way as much as possible.

This is set-it-and-forget-it software that handles the basic dangers, but doesn't try to compete with big-boy security suites such as those built by Symantec, McAfee or Panda. So you won't find extras such as a firewall, identity protection, anti-phishing technology or anti-spam. Instead, Security Essentials focuses on protecting you against viruses, spyware, rootkits and similar dangers, and does a very good job of it.

Those who have wrestled unhappily with the software's predecessor, Microsoft Live OneCare, will be pleased to know that Security Essentials suffers from none of the software bloat and slow performance that bedeviled OneCare. Unlike OneCare, Security Essentials doesn't do performance tune-ups, back up your PC, take up too much system resources - or cost a penny.

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Installation and setup

Security Essentials comes in versions for Windows XP and Windows Vista (the Vista version will also work with Windows 7). Both are light downloads: The 32-bit Vista download weighs in at 4.8 MB, the 64-bit Vista version at 3.8MB and the XP version (there's only a 32-bit version) comes in at 7.6 MB.

Installation of the 32-bit Vista version on our machine took less than five minutes and was about as simple as an installation can be. There is one caveat, though: You need to have a validated copy of Windows. Not surprisingly, Microsoft's software won't work with pirated or non-validated versions.

Microsoft Security Essentials1

Once installation is complete, the application downloads the latest anti-malware definitions. It then launches a quick system scan that took under ten minutes on my system.

Security Essentials uses a new feature called the Dynamic Signature Service, which employs a variety of techniques to check for malware even before that malware's specific signature has been identified. Microsoft says Security Essentials emulates the behaviour of programs before they run, and uses the signature created during the process to look for any suspicious behaviour or patterns of suspicious behaviour, such as starting an unexpected network connection or trying to modify certain protected sections of Windows. The Dynamic Signature Service then determines what action to take against the potential malware.

Once the software has scanned your system, you don't need to do anything else, unless it finds malware that it wants to kill or quarantine. New anti-malware signatures are automatically downloaded daily, using the Windows Update engine; you can also have the software to check for the latest definitions manually. Security Essentials also provides real-time protection, so it watches your system as you use it and warns you if you're downloading malware or if your system has been infected. The software also scans your system once a week by default. You can manually override the defaults and set up specific days and times to perform the scans; more about this later.

NEXT PAGE: Microsoft Security Essentials in action >>

 

The just-released beta of Microsoft Security Essentials - not yet available in the UK - is a solid, free tool that protects against malware while taking up few system resources and staying out of your way as much as possible.

Microsoft Security Essentials in action

Most of the time, you'll only know that Microsoft Security Essentials is running because you see its icon in the System Tray. Other than that, it leaves you alone unless it finds a problem. It uses very little RAM or system resources, and we noticed no performance hit on my machine when it ran, except when it performed a scan. When it started the scan, my PC slowed down for the first several minutes of the scan, but then ran fine with the scan working in the background.

Scans and updates are scheduled to run when your PC is idle, although you can run a scan manually. They are given a low priority by the operating system, further reducing their impact on your PC. In addition, CPU throttling is used to ensure that the software doesn't use more than 50 percent of your CPU.

Microsoft Security Essentials2

When Security Essentials finds an infection on your system, you can have it immediately take action against the threat, or you can click Show Details, at which point you'll be shown as much information as the software has about the threat.

When you lick on the Clean Computer option, Security Essentials will either delete the file or quarantine it, depending on the nature of the threat.

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Easy interface

Most of the time, that's all the interaction you'll have with Security Essentials - there's very little need to open the program for any other reason. However, if you do open it to, for example, customise its actions in some way, you'll find a very simple interface that to a certain extent mimics the look of Windows Defender.

There are four tabs - Home, Update, History and Settings. Home shows you the status of the software and your system and lets you perform a scan; Update shows you the status of definition updates and lets you update them manually; History shows you a history of the actions the software has taken.

Settings lets you change most aspects of how the program works, including when to perform scans, the type of scan to perform (Quick or Full), what actions to take when an infection is detected and the ability to exclude files, locations and processes from scans. There's actually little reason to change any of the defaults, although it's nice to know you can.

When customising, keep in mind that a Full scan takes significantly longer than a Quick scan. On my system a Quick scan took under ten minutes; a Full scan took more than an hour.

There are anti-malware applications that offer far more customisation than does Microsoft Security Essentials. Avast!, for example, lets you finely tune the sensitivity of its scans, so that you can make them more or less aggressive; you can't do that with Security Essentials. Most people won't miss it, but security tweakers may not be satisfied with the level of customisation available.

NEXT PAGE: how safe does it keep you?

The just-released beta of Microsoft Security Essentials - not yet available in the UK - is a solid, free tool that protects against malware while taking up few system resources and staying out of your way as much as possible.

How safe does it keep you?

Until Security Essentials is put through its paces by antivirus labs, there's no definitive way to know how it stacks up against other applications. However, it shares the same engine and signatures as other Microsoft anti-malware products, including OneCare, the enterprise-focused Forefront and the monthly Microsoft Malicious Software Removal Tool. Therefore, looking at how OneCare compares should give some kind of guidance.

Microsoft Security Essentials3


In its earliest days, OneCare did not perform impressively in anti-malware tests, but over time that has changed. It now ranks near the top of security software, according to the independent AV-Comparatives website. The site regularly tests antivirus tools, and its latest tests of 16 applications, done in May, ranks OneCare as only one of three tools given the top Advanced+ designation (the other two were Kaspersky and ESET NOD32). It also tied for second place for its proactive detection of new malware and was the only software rated as giving very few false alarms.

The bottom line

In its reviewer's guide, the Microsoft says that "a surprising number of consumer PCs remain unprotected" against malware, although it offers no numbers. There are several reasons that consumers don't protect themselves, according to Microsoft. They are confused by the trial offers that come pre-installed on their PCs and by annual subscription fees. Heavy security suites slow down PCs and so people don't want to use them. Finally, some people simply aren't willing to pay for security.

Microsoft also notes that in "emerging markets," credit isn't always easy to come by, and so people can't pay for annual subscriptions using credit cards the way they do in countries such as the US.

NEXT: our expert verdict >>

OUR VERDICT

There's a lot to like about Microsoft Security Essentials, but we were a little disappointed by its malware detection and attack blocking - after all, antivirus software is only as good as its ability to keep your PC protected. Hopefully, Microsoft will bolster Security Essentials' threat-blocking capabilities in a future update, but until then, you'd be better served by going with something having better detection capabilities, such as Avira AntiVir Personal.

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