Also, Microsoft has an incentive to eliminate viruses and malware completely - to make their OS safer. Third party AV companies rely on continuing threats to stay in business. I'm not saying AV companies hold back or help malware out, I'm saying Microsoft has good reason to throw huge resources at the problem as a whole.

...and to build on your comment: Incentive to not slow down the performance of the OS while protecting it.

That was what caught my eye about MS's antivirus offerings from the start. I was really impressed how well it ran without me ever noticing.

I got a new laptop from work recently and I didn't spend a great deal of time looking it over as i was busy and ... of course I hit some random performance problems as McAfee was abusing my machine while I was trying to work. Endlessly installing antivirus programs is getting pretty old.

I had to help some regular computer user to clean their computer; one of the user's requests was to "fix" their McAfee, meaning, to update the subscription and solve other "security threats" (not viruses) that McAfee reported. After seeing how indecent this antivirus is, how it uses real intimidation, and is very intrusive with constant pop-ups, we settled on not continuing the subscription and getting rid of it altogether.

I was dealing with MySQL running on a Windows server box with McAfee Active Response running (MarService.exe). It has a feature for tracking files created/deleted, which is accomplished by hashing all new files, saving them to its own local DB, and presumably pushing them to the management server async. The app running on MySQL frequently creates many new tables and fills them as part of SOP, so the disk was constantly hammered by both MySQL and McAfee...

Windows Defender is the worst-performing antivirus on the market so that logic flies out the window.

Can you undergird this claim? (serious question, no flaming)

I disagree that this incentive differs for Windows Defender vs other AVs.

All AV software has the desire to not negatively impact performance because if it's horribly slow people will uninstall it / quit paying for it.

The parent comment is pointing out that companies which primarily produce AV products benefit from the continued existence and fear of malware (to a degree at least). This is different for MS, as the eradication of Windows viruses will help Windows, which should be large enough a benefit to override any perverse incentives Windows Defender would otherwise have.

I know what you're trying to say is "also, Windows Defender isn't as slow", which happens to be true, but I think that's simply an emergent effect of other factors, such as AV companies feeling the need to "do more" to add value (whereas Windows Defender is funded by MS, so it has less incentive to "stand out").

> Third party AV companies rely on continuing threats to stay in business.

i'm pretty neutral on this topic, but doesn't this point by extension mean they have a more direct interest in discovering security flaws and publishing them rather than burying them under the rug if they haven't been seen in the wild?

I think they share the same incentives in the sense that discovering, patching and reporting flaws is the mission statement.

Where they differ, I think, is the end goal. Non-MS AV need an ecosystem where there is still active threats to make revenue. MS actively doesn't want any threats, because they would realize more profits through their OS being marketable as virus-free.

I'm not saying Non-MS AV is out there introducing threats. But, they are incentivized to play whack-a-mole with bandaid fixes (keeping the ecosystem in check but alive) whereas MS is incentivized to go after root problems (kill the virus ecosystem, profit from OS).

What would you suggest for Mac and Linux? I lot of enterprise contracts and security certifications require "anti-virus installed and up-to-date".

What's the best way of meeting that checkbox for Mac and Linux laptops?

Install ClamAV but don't run the daemon?

I've had something similar happen, VirtualBox has measures to try to detect if it's been hijacked, by malicious software or AV (although the distinction could be argued).

Windows Defender is on every machine, so what would be the point of writing a virus that is detected by it? The same for Kaspersky. These programs are easy to test against and well-known. They are designed to work against old viruses that have already been detected and analyzed.

It's better to use lesser known antivirus products with good heuristic detection. I will not mention names but there are a number of products out there, including ones that block every executable not on a whitelist.

You can't just wave your hand and say that some lesser known "no names mentioned" product is better than Defender because you want it to be. If you have evidence that some AV product is out-performing Defender, it's extremely selfish and negligent to keep that information to yourself.

I'd much rather trust MS with Defender over some lesser known AV product which likely doesn't have billions of dollars, unfathomably large samples/datasets, and extensive experience with APT's.

As pointed out, no one really has a better incentive to detect and eliminate virus's than MS does in an effort to make their OS virus free.

Fair enough, but I did give a concrete reason why I believe some "no name mentioned" products may be better than Defender and other common antivirus products.

They will not only detect existing viruses. AV software has used heuristics to detect viruses for decades, and more recently ML is being used. Microsoft has really been investing in Defender and Defender ATP recently and there have been several Twitter and blog posts about the successes their ML approach is yielding, including for new viruses.

A lesser known anti-virus will also be from a smaller vendor with less resources to get 0day malware into their signature databases or maintain a good heuristic detection. A lesser-known AV with a good signature DB and heuristic engine is a unicorn.

I disagree with the point you made about 0days and detection rates. Defender has less false positives, but almost never catch the files that actually matter, like important 0days or antiemulation and anti-unpack files. They are pretty slow with crafting generic detections.

While I understand that data from well known tests may support your point, as an employee for 2+ years at a security vendor I can say with certainty that defender falls way behind when it comes to fast generic detections and response time. I quite frequently find myself copying maliciois files to my work laptop with defender activated and the detection rate is pretty poor as shown by the actual number of files that got copied. Not even mentioning how it quietly scans my files and activates itself even though I singlehandedly shut it down a minute ago

So presumably you have a product in mind which did catch all of these things, and are willing to point people in the proper direction?

What I can say from a more or less objective standpoint, the best vendors according to a response-time metric are Eset, Kaspersky and Bitdefender. Each of them have their own weaknesses and I do not know what is the performance impact for using them alongside defender

Interesting, thanks for answering. Is this object standpoint of yours from 3rd-party studies of response-time metrics, or anecdotal data from yourself?

Also, how substantial are these differences? Is it worth (in your opinion) being MitM'd by Kaspersky to realize the supposed benefits?

The data is empirical, based on comparative results of some files I've mananged to get my hands on over the years. I can't argue on MitM, because I haven't worked with traffic and traffic analysis, but when it comes to malicious executables and exploits, it's definitely worth the mitm inconvenience.

Ironically speaking, privacy concerned users are mostly IT-versed which can evade most of malware effects by just being attentive and caucios, while my mother, for example, doesn't care about MitM'ing her traffic, while I do care about her vising some shady sites while watching her beloved internet series.

Bottom line, if you are well versed, you probably can limit yourself to the default windows defender, but when it comes to successful unreleased exploits or a computer/user that is likely to download/run unknown executables some high-end vendor might be faster than other researches