Avast Web Shield slowing down/blocking Dropbox uploads

Hi Avast team and community,

in the last week I have noticed that Dropbox uploads (especially from the Dropbox Desktop App) are immensely slow or not working while my internet connection upload speed seems to be fine. (Dropbox downloads are instantaneous as always.)

Symptoms: I drag something into my dropbox folder, for example a 15 MB picture, and it appears to start synching. The Dropbox application reports ridiculous upload speeds of several thousand kB per second, but nothing gets uploaded - the synch just hangs there (I checked the clock - way more than half an hour, then I gave up). Sometimes something gets uploaded after a long while, but most of the time, it just appears to hang indefinitely.

I suspected Avast and played around with it a little bit - if I close Dropbox, then disable Avast’s Web Shield, then start Dropbox again, file uploading works as expected (15 MB take about a minute). Once I restart Web Shield, the uploading hangs again.

My system is Windows 7 x64, I’m running the newest Dropbox version (2.6.2) after completely uninstalling and reinstalling it. My Avast version is 2014.9.0.2011.

I found postings in the Dropbox forum where several people report problems that sound suspiciously like mine: https://forums.dropbox.com/topic.php?id=109525&replies=28#post-584274 and, more importantly, https://forums.dropbox.com/topic.php?id=109264 .

The suggested workarounds in the second link of adding the Dropbox folder paths to “status”->“antivirus”->“exclusions”->“directories” do not seem to work for me. Closing Dropbox, disabling Web Shield, restarting Dropbox always does the trick. However, I’m not too fond of the idea to disable Web Shield all the time.

Please tell me a (useful) workaround or try to fix this! It makes Dropbox completely unusable for me! :expressionless:

(I’m sorry if this was already reported, but I didn’t find anything when I looked and searched!)

Yours
Anne

Hi all and sorry for my English.
I have just the same problems (and quite the same configuration) described above.

But I solved “my” issues totally excluding the directory C:\Users\USER\dropbox* by Avast! antivirus controls, as described here: https://forums.dropbox.com/topic.php?id=109264

Anyway I hope this bug will be eliminated, as soon as possible.

Thank you for your attention.

This bug is still not fixed. :expressionless: Is there anything I could do to bring it to the attention of the avast team?

I just signed up to report a similar experience, hope adding it in this thread is alright (seems like the same bug).

Sometime late last week I started experience intermittent problems connecting to certain websites, specifically I’d get served what appeared to be blank pages (but looking at the source revealed there was indeed HTML etc present). Sometimes reloading the page a few times would fix the issue; sometimes it would produce only a partially loaded/rendered page; it would also sometimes corrupt images. Additionally, I began experiencing connectivity issues with MSN Messenger (using Trilliam IM), but Skype and others worked fine.

I proceeded to do a lot of troubleshooting (I have 20 years in IT, I occasionally have some clue what I’m doing): I originally felt it was a firewall issue but I finally traced the problem to Avast’s Web Shield. It wasn’t doing this before, so I can only conclude something changed in the last update (which I vaguely remember installing last week).

Shutting down Web Shield fixed the issue. Shutting down individual components of web shield did not. I’ve now reinstalled Avast without the Web Shield module and everything is back to normal.

Not really a lot of use without vital information as to what operating system is involved, or exactly what version of Avast you have. Your reference to firewall does not say whether it is an Avast firewall, or a third party firewall.

Anyhow, if your OS is Win 7 or above, I suggest you read the thread at http://forum.avast.com/index.php?topic=143211.0 That contains at least two possible fixes for the Web shield. If you are using XP then forget it, because the fixes don’t apply.

Whilst I personally don’t have the browser AOS addons installed, I wouldn’t recommend running without the Web Shield enabled.

I have a similar problem.
As I work from home I have to log in to the system of my employer and also use FTP-access to upload/download files. Everything was fine up to one of the last updates. Logging into the system sometimes takes minutes and sometimes I have to retry it several times. Getting the folder structure in the FTP-program doesn’t work anymore, thus I cannot upload/download files.
When I disable the the Web Shield everything is working great again.
I also noticed that I cannot use a speedtest for my internet connection anymore when the Web Shield is active. It seems that every upload is blocked by the Web Shield.

I’m using Windows 8.1

Could it be because of redirects like this one for example: https://www.dropbox.com/downloading?src=index redirects to https://www.dropbox.com/install?src=index
This scam malware is being blocked by avast! http://support.clean-mx.de/clean-mx/portals?id=2731585
Long overdue malware up and active and now running for 2812.5 hours.
That server there is being abused and misused! See safe Scam Viewer: http://support.clean-mx.de/clean-mx/view_portalscontent.php?id=2731585&url=https%3A%2F%2Fwww.dropbox.com%2Fs%2Frhlwt3xbhp2zw4y%2Fz508B2.html
Ask the dropbox folks to cleanse this. It is a valid detection. Sloppy IT is at the root of a lot of problems!

Chinese hackers and other malcreants, trojan downloaders all do their mean deals at dropbox, read: http://www.techrepublic.com/blog/it-security/dropsmack-using-dropbox-to-steal-files-and-deliver-malware/ link article author: Michael Kassner

polonus

Thanks for the reply.

OS is Win 7 x64 SP1 (updates kept up to date); Avast is 2014.9.0.211 (latest patch applied, aswstm.sys is …265).

Several firewalls were in play while I was testing: most used was an old ZoneAlarm (version 9.x) which I still had the install for and trusted as working properly. I also used the latest version of Comodo Firewall (6.3.x) which is what I’m back on now (see below).

As outlined in thread you linked, I’ve reinstalled the Web Shield module and ensured the latest version (265) was in use: the problem re-appeared; I proceeded to apply the “UseStreamFilter=0” change in webshield.ini and am currently testing that: preliminary results would appear this action corrected the problem. Testing is ongoing. If everything looks normal I’ll try installing the updated aswStreamFilter.dll.

Another, apparently related issued I’ve noticed when Web Shield is enabled – and the reason I’d originally uninstalled Comodo – is its cmdagent.exe process seems to get stuck at times, using a steady 50% CPU load (obviously this is totally unacceptable, so not knowing what the problem was at the time I dumped Comodo). After disabling Web Shield I reinstalled Comodo and low and behold, it was functioning properly (tested for 24+ hrs – which is plenty, usually it racked up hours of CPU Time in that timeframe). Keeping an eye on cmdagent.exe’s CPU usage is now part of my testing for Web Shield fixes.

The “UseStreamFilter=0” solution appears to have corrected that issue as well. I see some small spikes of CPU usage that weren’t happening when Web Shield was disabled, but nothing excessive so far. But there’s definitely some interaction going on there. (note that I’m not 100% sure what it is cmdagent.exe actually does as it keeps “doing stuff” even with all the Comodo modules disabled).

Still not sure whether you are using the free version of Avast (which doesn’t have a firewall componenty) or one of the paid versions that does. If it is the latter, I would disable the firewall whilst you are using the Comodo one.

Several firewalls were in play while I was testing: most used was an old ZoneAlarm (version 9.x) which I still had the install for and trusted as working properly. I also used the latest version of Comodo Firewall (6.3.x) which is what I'm back on now..
There are reports elsewhere in the forum that suggest there might be some compatability issues with ZoneAlarm, but a number of users have reported they don't have an problems running Avast with the latest Comodo Firewall
Testing is ongoing. If everything looks normal I'll try installing the updated aswStreamFilter.dll.
Don't forget when you do to remove the "UseStreamFilter=0" change

Please post back your results when you have tried the aswStreamFilter.dll change.

Could you try the latest beta?http://forum.avast.com/index.php?topic=144768.0

Edit: fixed the link

Olddog, my appologies: I’m using the free version of Avast without the firewall (and also the free version of Comodo without the AV).

During my testing with Zone Alarm (free) I had no issues, but it was an old version (9.x; current is 12 if I’m not mistaken). I opted for the older version because I don’t like some of the functionality changes in the newer version and I’d run it with previous versions of Avast on another machine previously, without problems.

Just to update my current testing:

Those CPU usage spikes with Comodo’s cmdagent kept happening, more than with Web Shield disabled; it didn’t take long to see this was occurring way more than usual (racked up 10 minutes of CPU time in only a few hours). So I installed the newer version of aswStreamFilter.dll (yes, did remove “UseStreamFilter=0” ) and now everything is 100%. Browser and IM functionality is flawless, and cmdagent is behaving normally (by way of comparison, uptime is now 4 hours and its CPU Time is 4 seconds).

So as far as my problem is concerned, version 9.0.2194.269 of aswStreamFilter is a winner.

@Lukor, I will try the patch tomorrow and report back. Thanks!

That link isn’t pointing to the new beta lukor, this one will http://forum.avast.com/index.php?topic=144768.msg1049924

Quick update, seems I may have spoken too soon.

After several hours of everything working flawlessly, I had to reboot (reinstalled my scanner); upon reboot some websites wouldn’t load properly again (however, cmdagent.exe does not appear to be using CPU excessively, not even small spikes).

Disabling Web Shield fixes the problem. I checked aswStreamFilter, still version 9.0.2194.269 installed. I tried the “UseStreamFilter=0” config, this time it made absolutely no difference (still with aswStreamFilter 269).

Very strange.

Also because I’ve been re-opening the same websites to test, I can tell that with Web Shield active they do load slightly more slowly). This is only when broken, when Web Shield is off its fine and when 260 was working good it was also full speed.

I guess I will try the new beta next!

Well, first of all my apologies, I feel like I’ve hijacked this thread with my own posts/observations. Hopefully the solutions that worked for me will at least also be of use to Zai and others.

So I installed the beta (…2012) this morning and it seemed to behave well. I rebooted a few times and then proceeded to update some drivers (with more reboots), waiting about an hour between each to see if anything abnormal started happening: so far the beta is behaving flawlessly; no adverse interactions with Comodo Firewall (cmdagent.exe), all websites (http and https) are loading quickly and without glitches, no problems with IM connectivity; also seemed several emails with nefarious attachments got past my spam filter today and Avast, as usual, did a splendid job of catching them as soon as they downloaded, so everything seems to be working fine on that front as well.

I will continue testing but so far the beta gets a thumbs up.

Thanks for that info Drake… I won’t be able to install the beta right now, but let’s hope that if the WebShield is working for you in the beta it will also work for the Dropbox problem when it’s finally distributed… xD

Hi Guys, I have had issues uploading files to dmcloud and sproutvideo. when uploading files I have found the upload speeds have become unrealistic and have caused my computer to think it is running on a ultra fast connection. The fact remains this isn’t true and I discovered the Web Shield was causing the problems. I installed the latest beta 2012 however this has not fixed the shield in fact its caused the avast UI to crash even more.

I just wanted to let you know your not alone with this problem. Hopefully Avast will fix this as soon as possible.

After a full day running the 2014.9.0.2012 beta, doing a few software installs/updates and some driver updates, lots of resets, visiting extra websites to get updates (in addition to my usual batch I was visiting to test before), everything seems 100%.

sadly not here :frowning:

I noticed, that trying to use webupload to different sites show the same
problems as Dropbox uploads - first incredible speed, but no uploading
after all.

I tried repairing, the fix, the beta, but only deactivating web shield helps -
but also that makes in 70% a freeze of Avast.

I am quite busy with rebooting my computer all the time, till I finally get
the f****** webshield down.

I’m getting the exact same problem here.

I had to uninstall Avast to make my dropbox work again.

Hi Guys, I am compiling logs to send off to Avast. I have created a forum topic in the Beta Forum with the hopes of getting this fixed for everyone.