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When downloading files from the Internet in browsers such as Chrome it seems that they set a flag of some sort on the file telling Windows that the file was downloaded form the Internet and that it might not be safe.
For a lot of files this does not cause a problem, opening the file happens fairly quickly prompting me to enter admin mode for the install if needed.
It seems however that for programs with less “reputation,” maybe they don’t have a digital cert or maybe they have only just been released, Windows takes a long time to open the file. Sitting there apparently not doing anything for up to 10 minutes before it finally decides to open the file.
Of course in this time I might have tried to open the file more than once, in that case both files execute at the same time once Windows decides it has checked whatever it needs to check.
I notice that for these files even opening the properties of the file in Windows explorer is very slow, taking the same amount of time. When the file properties do finally open I see an 'Unblock' option in there. I believe this is the flag causing the problem.
Does anybody know what is causing this and how to stop it? It is very annoying. I don’t really know what is responsible for it, maybe Windows Defender?
This happens on all my Windows machines including a fresh install of Windows 8.1 that was installed yesterday. The only antivirus running on the machine is Windows Defender that came with Windows 8.1. There are no other security, adware or malware programs installed.
An interesting note is that if I use a download manager to download the file it seems that this flag is not set on the file and the files always open straight away.
UPDATE1 (include comments summary):
Browsers Affected:
Chrome: Very slow to open properties / execute file after download
Internet Explorer. After download runs 'security scan' which takes maybe 10 seconds then opens instantly both in IE and Explorer
Anti-Virus:
- Windows Defender
- MalwareBytes (on one machine but not another that is also affected)
- Download Managers (such as Download Ninja), files open straight away, no delay
Possible Causes / Solutions:
Disable Windows Defender:
- This does not seem to have any effect on the time required to open a file
Caused by large file size?:
- The files I am testing this with are only about 5-6mb so I am not sure this is the case
Happens with all files?:
- If it download a well known file such as putty it opens straight away
Enable 'Do not preserve zone information in file attachments' in Policy Editor:
- This stops the 'Unblock' button from being shown in properties but it does not appear to speed up the opening of the file. In my tests after setting this option files still take ~30s-4m to open after download
ant-fx
Posted 2014-12-04T11:51:10.623
Reputation: 193
Does this happen with Firefox or Internet Explorer ( with the same file ) – Ramhound – 2014-12-04T11:56:13.693
I just downloaded the same file in IE and it ran a security scan after the download. That took about 20 seconds and after that the file ran quickly. That might be because of the security scan resetting the 'Unblock' flag or maybe because I had already downloaded it earlier? – ant-fx – 2014-12-04T12:01:18.293
What is your installed security suite or antivirus? – harrymc – 2015-03-05T08:58:37.683
Windows Defender + Malware Bytes but I have this problem on machines that only have Windows Defender installed. Perhaps something to do with my location? Internet speed is OK however (12mb/1mb) – ant-fx – 2015-03-05T09:33:08.950
It seems that the problem only happens on files that are marked as unsafe because coming from the Internet. What happens if your disable Windows Defender? – harrymc – 2015-03-05T13:31:06.010
Does this happen with all files you download in chrome, can you a give a specific file that behaves this way? – Cosco Tech – 2015-03-05T13:37:54.953
@harrymc disabling WindowsDefender does not appear to improve things. – ant-fx – 2015-03-05T13:51:53.067
@GarettCosco it seems to be with files that do not have much reputation. For example, I work for Easy-Hide-IP, if I release a new version and upload it and then download it again to make sure all works as expected it takes a very long time to open yet if we release that version after a few days a newly downloaded file will open much more quickly. The time taken to open is also very variable, sometimes around 1m and sometimes 10m – ant-fx – 2015-03-05T13:52:02.433
Ok, is it just that specific file/program? – Cosco Tech – 2015-03-05T13:55:46.983
no, can be anything downloaded from the Internet – ant-fx – 2015-03-05T13:59:33.703
And I'm pretty sure it has to do with the flag that the file came from the Internet. Using a download manager that does not set this flag files open straight away http://cdn.easy-hide-ip.com/downloadFromInternet.PNG
– ant-fx – 2015-03-05T14:05:09.847Ok, can you download a reputable program and verify that it behaves the same way, then post the name of the program/file and its download location. Also, what happens when you hit that unblock button, does the file open quicker? – Cosco Tech – 2015-03-05T14:50:13.663
What happens if, before execution, you in the Properties of such a downloaded file unblock it, so unmarking it as unsafe? – harrymc – 2015-03-05T15:52:11.007
@GarettCosco Downloading reputable file such as putty.exe opens properties near instantly. – ant-fx – 2015-03-05T16:31:58.783
@harrymc Opening the properties page takes equally long to complete as executing the file (1m to 10m) once open and I click unblock executing the file and opening properties instant. – ant-fx – 2015-03-05T16:32:43.557
@user1167223 I think what matters most isn't the "reputation" of the file but merely its size; ie. all files are checked (possibly hashed and compared with the hash of their signature, if any), and you just don't notice it unless the file is quite large (I've seen this issue myself when running a 1,7GB .exe file back in the Vista days). – None – 2015-03-05T16:42:57.130
This is too weird, so must be caused by some software product. This can be checked by booting into Safe mode to see if the slow-down disappears. If it does, then for example Autoruns for Windows can be used to see all startups and turn them easily off/on until the culprit is found.
– harrymc – 2015-03-05T16:46:15.570I was running into this issue back in December as well, but haven't lately. Perhaps Microsoft was just having issues with the servers that run the reputation checking stuff? – Keith Lammers – 2015-03-05T16:55:18.943
Could you open the resource monitor and go to the "Disk" tab. Sort the "Disk activity" (second window) by filename. While experiencing your lag, check which Image (application) is mentioned next to the filename you are trying to open. Let us know what you find there, because that's the application that is locking your file for such a long time.
– agtoever – 2015-03-06T08:25:37.230Being that number of reasons that could cause something like this are nearly unlimited, I suggest running Process Monitor while reproducing the problem. This will generate log of pretty much everything that occurred along with processes and timestamps. From there, you should be able to discover the culprit. If you are comfortable with such, posting a log from this may be very helpful. – NuSkooler – 2015-03-12T03:24:04.943