SeriousHoax

Level 6
Verified
Malware Tester
The issue is anti-viruses like AVG, Avast, Emsisoft, Eset, Mcafee don’t scan files when I enter into a folder. What I mean is, if in a folder there are few malwares with .exe extensions or else and I enter into the folder, the anti-viruses that I mentioned above don’t detect and remove them. Even if I single click on the malwares they do nothing. They only detects when I double click/scan them. I don’t understand why they comes with this settings by default. This surely improves computer performance by a little but this is wrong. AVG didn’t used to be like this. They used to scan files based on file extensions by default but after the AVAST accusition they became like AVAST. Shame. AVG and AVAST probably have options to scan all files on access or by file extensions but I didn’t find any on Eset maybe because I didn’t look thoroughly enough. Same goes for Emsisoft and stupid Mcafee doesn’t really give options to customize their settings. These are just the one’s I personally tested recently so I’m sure there are more Avs out there with similar default settings. Quality products like Kaspersky, Bitdefender, Norton and even built in Windows Defender scan all the files. If they don’t change this then AVG, Avast, Emsisoft, Eset, Mcafee are kind of useless to me. I uninstalled them immediately.

Let’s discuss this and if you know possible solutions to change this behavior of these avs then posting them would be very helpful.
 

roger_m

Level 23
Verified
Content Creator
Scanning all the files in a folder when you open it, does decrease performance. A good example of this is Windows Defender and this is one of the reasons why I never use it.

If you launch a file, it will be scanned before it is opened, so in my opinion, it doesn't matter if the contents of a folder aren't scanned when you open it.
 
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SeriousHoax

Level 6
Verified
Malware Tester
Scanning all the files in a folder when you open it, does decrease performance. A good example of this is Windows Defender and this is one of the reasons why I never use it.

If you launch a file, it will be scanned before it is opened, so in my opinion, it doesn't matter if a the contents of a folder aren't scanned when you open it.
The performance impact is pretty low actually in my experience. You can check the performance report on AV-Comparatives and AV-Test too. Not much of a difference. Defender, Kaspersky, Bitdefender doesn't really slow down pc, they are well optimized.
 

devjit2018

Level 12
Verified
Malware Tester
There is actually no benefit from scanning files while opening a folder unless you execute the files. I don't know how you tested ESET but in my case ESET IS deletes the infected executables as soon as I open any folder. The main point of an antivirus is to prevent the execution of malwares. So if an antivirus detects while executing a file its doing its job perfectly...there is no need to complain. Defender certainly slows down if you open a folder with a lot of executables. In comparison Kaspersky and Bitdefender are much lighter. But if you compare ESET with any of those, in terms of lightness ESET blows them away.
 
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roger_m

Level 23
Verified
Content Creator
The performance impact is pretty low actually in my experience.
It's slows my computers down.
You can check the performance report on AV-Comparatives and AV-Test too.
There's a big issue with performance reports. The performance of antiviruses can very greatly from one computer to the next. I often find that that the results in performance tests are very different to what I experience. The reality is that the best way to test performance, is by installing a product on your own system and testing it yourself. What works well for testing labs or other people, may not work well for you.
Defender, Kaspersky, Bitdefender doesn't really slow down pc, they are well optimized.
I disagree. Or to be more specific, for some people they are really light, for others including myself they cause slowdowns. A good example of this, is that if you read posts here about Windows Defender, while many people fine it to be fairly light, for some people it causes slowdowns on high end gaming systems.
 

Upendra19

Level 1
The issue is anti-viruses like AVG, Avast, Emsisoft, Eset, Mcafee don’t scan files when I enter into a folder. What I mean is, if in a folder there are few malwares with .exe extensions or else and I enter into the folder, the anti-viruses that I mentioned above don’t detect and remove them. Even if I single click on the malwares they do nothing.
I don't agree. On my laptop Avast removed malicious .exe file immediately after opening folder. In past the lightsest ESET also deleted malicious files just after opening folder.
There's a big issue with performance reports. The performance of antiviruses can very greatly from one computer to the next. I often find that that the results in performance tests are very different to what I experience. The reality is that the best way to test performance, is by installing a product on your own system and testing it yourself.
(y)
I installed Kaspersky yesterday and it is lighter than Avast but the lightest was ESET. Defender was heavy.
 

Spawn

Administrator
Verified
Staff member
No need to get upset over the default settings. If it can be changed, do it. If not, find another software.

You should see the amount of users who complain about Windows Defender Antivirus being "slow" because it scans the folders when opened by the user.
For example: "Don't use WDA because it's slow to scan 1000 executable from my Downloads folder."

There are also a ton of other factors; laptop (battery saver) vs desktop (mains power), Power plan, CPU/Storage type etc.

Bottom Line: Don't lose sleep over it.
 

Atlas147

Level 30
Verified
Content Creator
Scanning when a file is executed is definitely the standard now. Imagine your AV having to scan 100 files each time you open a folder to go open something, it's just simply not feasible.

There is no real loss in protection because if the file were to be picked up by the AV it would be detected when it's executed, if it's not executed then it wouldn't cause any real harm to your computer, a win win situation.

This is also the reason that you should run periodic full system scans of your computer to do a sweep if the AV had missed anything initially.

On top of this, the AV not only relies on signatures but also behavioral blockers that only function while a program is being run. There is just no way to "virtually" run all programs to get the program against the AV's behavioral blocker.
 

LDogg

Level 29
Verified
You can check the performance report on AV-Comparatives and AV-Test too.
Please take these tests with a pinch of salt, they do not reflect real users that sit in their homes with daily usage of machines. Variety of factors come in, make/model of computer, drivers etc etc.

Back on subject :p

Do not lose sleep or get too anxious over default software settings, you can change these at any time by the user.

~LDogg
 

Raiden

Level 13
Verified
Content Creator
I agree with what others have said in regards to performance impact and performance tests. The problem with trying to assess performance is that it's not as simple as it's made out to be. There are way too many variables to properly assess the performance impact of an AV/Suite (ie: hardware/software configs, how one uses the computer, etc...). These tests try to make it cut and dry, when in fact it's not. All of these tests should be taken with a huge grain of salt, especially the YouTube ones because they tend to perform these tests in a VM. I'm sorry, trying to compare a system that runs directly on the hardware to a VM is just silliness. The VM will never, ever be as fast a running it directly on the hardware, so right there the VM is already introducing a performance impact of it's own.

Another thing that is often overlooked is how does the product impact the system over a longer period of time and not just the first day or 2 a test is ran? Many of these programs will develop large cache files and stuff over time, who's not to say that maybe 8 month's later it's not slower than it was before due to things like large cache files?

IMO another thing that cannot be overlooked is the simple fact that, with the software and hardware available today, we are able to measure things (like performance) that otherwise would not be noticeable to us humans. For example, a lot of people were performing tests of various products using Novabench. Lets say product x get a score of 700 and product y gets a score of 760, do you honestly believe you can actually notice that difference in the read world, my guess is it will be a no. You cannot forget how perception can play an impact as well. If people keep saying that x product is slow as molasses and it may be true, but is someone goes into it with a preconceived notion that it's "slow as molasses", chances are they will go , oh ya it is slow. Now the questions we have to answer are, how much of that is true, or how much of that is simply due to the fact that it really only took 1-2 second longer, but we perceived it to by way slower than it really was, simply due to the fact we went into it with a perceived notion that it was slow?:unsure:

To echo what other's have said, don't loose sleep over it.:)
 
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Local Host

Level 17
Verified
The performance impact is pretty low actually in my experience. You can check the performance report on AV-Comparatives and AV-Test too. Not much of a difference. Defender, Kaspersky, Bitdefender doesn't really slow down pc, they are well optimized.
Have you checked the performance tests yourself? Cause Windows Defender has the worst performance of the bunch right next to Malwarebytes. The reason for that is as @roger_m stated and well.

Is a waste of resources to constantly scan all the folders like Windows Defender does (especially when no changes whasoever were made since the last scan).

You'll find no lack of complaints about Windows Defender affecting performance, you instantly feel the PC faster the moment you disable it.
 

Raiden

Level 13
Verified
Content Creator
Have you checked the performance tests yourself? Cause Windows Defender has the worst performance of the bunch right next to Malwarebytes. The reason for that is as @roger_m stated and well.

Is a waste of resources to constantly scan all the folders like Windows Defender does (especially when no changes whasoever were made since the last scan).

You'll find no lack of complaints about Windows Defender affecting performance, you instantly feel the PC faster the moment you disable it.
Just playing devil's advocate here, but TBH I really don't notice it all either. If anything some things I've noticed from trying 3rd parties and going back to WD is that Windows boots and loads faster, programs open faster and web browsing is faster. To be clear, I am in no way saying that it doesn't slow things down and that it's all made up, its really there. I just think that it depends, that it can be different from person to person and system to system. For example, I don't have very many files on my computer, they are either stored in the cloud or on and external device that is disconnected. I also don't have a folder with 1000 exe's in it either, nor do I install and uninstall programs very often. Quite frankly if you want to look at the "tests," where does WD score poorly? Installing/uninstalling programs and sometimes file transfers. Other than that, the rest of the test(s) show it to be just as good if not better than some third parties, if your going by the tests.

I do think MS does need to change the way is scans as well as introduce some sort of caching, doing those alone would fix those problems and WD would be very snappy.:)(y)
 

SeriousHoax

Level 6
Verified
Malware Tester
Thanks everyone for sharing your thoughts. Now I understand why many AV's nowadays opting not to scan every files.
You'll find no lack of complaints about Windows Defender affecting performance, you instantly feel the PC faster the moment you disable it.
Actually, in my experience Defender is pretty fast. It only feels a bit slower when enter into a folder with lot of executables but that's very rare. Otherwise it feels very fast. Currently I'm using Kaspersky Free, weirdly it seems to slow down copying speed a bit but otherwise it's very fast too.
There is actually no benefit from scanning files while opening a folder unless you execute the files. I don't know how you tested ESET but in my case ESET IS deletes the infected executables as soon as I open any folder. The main point of an antivirus is to prevent the execution of malwares. So if an antivirus detects while executing a file its doing its job perfectly...there is no need to complain. Defender certainly slows down if you open a folder with a lot of executables. In comparison Kaspersky and Bitdefender are much lighter. But if you compare ESET with any of those, in terms of lightness ESET blows them away.
Actually, a year or two ago Eset did the same for me too but latest update didn't do so. Maybe they changed something now? I agree Eset is very fast indeed.
I disagree. Or to be more specific, for some people they are really light, for others including myself they cause slowdowns. A good example of this, is that if you read posts here about Windows Defender, while many people fine it to be fairly light, for some people it causes slowdowns on high end gaming systems.
True. I'm one of those people who finds Defender to be very light nowadays. A year ago it was slower but now it feels very fast.
There's a big issue with performance reports. The performance of antiviruses can very greatly from one computer to the next. I often find that that the results in performance tests are very different to what I experience. The reality is that the best way to test performance, is by installing a product on your own system and testing it yourself. What works well for testing labs or other people, may not work well for you.
I agree. Performance varies from PC to PC. I check their report just to get an idea of the performance.
Now the questions we have to answer are, how much of that is true, or how much of that is simply due to the fact that it really only took 1-2 second longer, but we perceived it to by way slower than it really was, simply due to the fact we went into it with a perceived notion that it was slow?:unsure:
Right. The difference is probably not much. Merely a second or two. It depends on the user whether they feels and accept this slowdown or not.
Scanning when a file is executed is definitely the standard now. Imagine your AV having to scan 100 files each time you open a folder to go open something, it's just simply not feasible.
This makes sense. In my case it's more down to peace of mind I guess. I usually used Kaspersky, AVG, Avira, Norton, Windows Defender for a longer period for the last 10-12 years. Among this only AVG changed the behavior and other are still continuing the traditional way. So, I'm more used to such config hence feel a bit insecure with the current standard.