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Consumer Products => Avast Free Antivirus / Premium Security (legacy Pro Antivirus, Internet Security, Premier) => Topic started by: rudolffischer on March 03, 2010, 09:48:12 PM

Title: webshield blocking web access
Post by: rudolffischer on March 03, 2010, 09:48:12 PM
Hi
since today, I cannot access the web anymore on one of my PCs. not with IE8, not with Firefox. I have XP SP3, Outlook 2007, IE8, Firefox installed. Avast Free 5.0.418. This happens only with the browsers. Outlook 2007 and other applications can access the web fine.
If I turn off "scan web (http) traffic", I can access the web with the browsers no problem.
On my other PC's with the same programs installed, I don't have this issue.
Does anyone have an idea what might be the problem?
Thanks and regards
Rudi
Title: Re: webshield blocking web access
Post by: DavidR on March 03, 2010, 11:28:11 PM
Sounds more like your firewall blocking avast's web shield function:
What is your firewall ?
Does it allow avastSvc.exe internet access ?
- If it does delete the entry for it and reconnect to the internet, this should force the firewall to ask permission again.
Title: Re: webshield blocking web access
Post by: cadremis on March 03, 2010, 11:39:13 PM
I guess something is happening since I have DSL and it is taking time to open pages with firefox
Title: Re: webshield blocking web access
Post by: Hermite15 on March 03, 2010, 11:42:09 PM
I guess something is happening since I have DSL and it is taking time to open pages with firefox

related to avast web shield ?
Title: Re: webshield blocking web access
Post by: Morgenstern72 on March 04, 2010, 01:21:12 PM
I have the exact same problem!
Yesterday all worked fine, today no Browser could connect (no problem for avast updates, google talk and so on).

This definitely has to do with some update of Avast or Microsoft. I have not installed any other web related product or firewall since months.

Windows 7 Enterprise 64bit
Avast 5.0418
Database 100303-0

Enabled Web Security stops surfing in any browser (tried Chrome 4, IE8, Firefox 3.6) but every other access to the internet is working.
Title: Re: webshield blocking web access
Post by: DavidR on March 04, 2010, 04:30:16 PM
Have you done as I suggested in my first reply and more importantly what is your firewall.
Title: Re: webshield blocking web access
Post by: Morgenstern72 on March 04, 2010, 05:03:36 PM
Have you done as I suggested in my first reply and more importantly what is your firewall.

Windows internal firewall.
There is no entry for avastSvc.exe. There either never was an entry or it was removed in mysterious ways from yesterday to today.
It's not asking to allow Avast to connect; it never has.

But I am willing to try a solution: what exactly do you want me to enter?

Thx alot for your time and effort to help me/us :)
Title: Re: webshield blocking web access
Post by: DavidR on March 04, 2010, 05:12:15 PM
Well by default the win7 firewalls outbound protection is disabled (so shouldn't be getting in the way) and as such should not get in the way. So have you got the outbound protection enabled in the win7 firewall ?

Do you connect to the internet using a web proxy ?
Do you get any errors displayed ?

You could try manually setting the browser to use the avast web shield localhost proxy, see below, whilst these may not be for your version of IE or Firefox, you should be able to find the corresponding settings:
For IE - broadband users: - Tutorial - Web Shield Proxy Set-up for IE (http://www.avast.com/files/tutorials/ws_ieproxy.htm)
For Firefox users - Tutorial - Web Shield Proxy Set-up for Firefox (http://www.avast.com/files/tutorials/ws_ffproxy.htm)
Title: Re: webshield blocking web access
Post by: Morgenstern72 on March 04, 2010, 05:39:37 PM
Outbound: allow default (no block outbound rules)
Proxy: I connect directly to the internet, no proxy (no DSL, no dial in)
Errors: no errors. The browsers can resolve the names but you can see no website. It tries to connect and tries and tries and after some time a blank screen comes.

I for sure do not want connect over the avast proxy. I am very happy that I am not forced over some proxies and I do not want to start with it just because my antivirus does not behave from one day to another.

By the way, Avast Support wanted a HiJackThis Report from me which I sent them. It seems obscure to me that they suggest some virus on my system that causes this behavior but maybe there is something like that. Spybot (no resident parts running) did not find anything.

PS: the only thing i installed yesterday was Chrome 4 and Windows Defender Updates. All was running fine and I shut down my PC allowing it to install the windows updates. Starting the PC today and no surfing possible.

Title: Re: webshield blocking web access
Post by: DavidR on March 04, 2010, 06:50:51 PM
You aren't connecting 'over the avast proxy' you connect as normal to the internet. However, normally what happens when browsing, the web shield transparently intercepts http port 80 traffic. For whatever reason this isn't happening the manual setting of the browser proxy so that http port 80 traffic can be scanned protecting your system from internet malware.

If nothing else this will give an idea of what is being blocked, if the browser can display the pages and web shield is able to scan that content, then something is blocking the web shield proxy.

Unfortunately, I can't be any practical help with win7 or windows defender as I don't use either of those.
Title: Re: webshield blocking web access
Post by: robert8199 on March 05, 2010, 06:12:51 PM
I have the same issue. Here are some things I have found.
Windows XP Pro SP3
Avast 5.0.418
Verizon FIOS 50MB through Sonicwall 2040
With default settings http access is blocked. Can ping yahoo.com but cannot retrieve web page.
Since I can ping that means DNS is working. I tried setting proxy to localhost 12080. Did not change anything. Turn off the shield and web browsing works. Turned off Windows firewall, no change.

2nd PC
Windows XP Pro SP3
Avast 5.0.418
Verizon FIOS 50MB through Sonicwall 2040
Only difference is I installed Flashpeak's Slim Browser
Through slim browser can access webpages.
IE8, Firefox, Chrome all fail.

Went back to the first computer and installed Slim Browser and it will access web pages through slim browser only. All settings were default.
Title: Re: webshield blocking web access
Post by: Lisandro on March 05, 2010, 06:28:39 PM
Is everything right into your hosts file?
Any other security program that could interfere?
Does it occur with every browser?
Title: Re: webshield blocking web access
Post by: Morgenstern72 on March 05, 2010, 06:56:27 PM
1. Is everything right into your hosts file?
2. Any other security program that could interfere?
3. Does it occur with every browser?

1. Yes, only wanted entries (but you can give me some hint for a tracerout if you think theres a problem reaching some sites)
2. No
3. Yes (IE 8, Firefox 3.6, Chrome 4)
Title: Re: webshield blocking web access
Post by: Lisandro on March 05, 2010, 07:01:19 PM
Sorry, I'm not an expert on tracerouting.
I have one website that I can't reach also and never find how to solve this.
Title: Re: webshield blocking web access
Post by: robert8199 on March 05, 2010, 07:44:14 PM
1st PC is a new build clean host file.
2nd PC about 3 months old clean host file.
I only have Avast 5.0.418 on 4 computers
have Avast 4 Pro on about 120 computers all with no problem
Title: Re: webshield blocking web access
Post by: frozensnack on March 24, 2010, 05:56:12 AM

Duplicate post here http://forum.avast.com/index.php?topic=54300.0 (http://forum.avast.com/index.php?topic=54300.0).

Same issue with my Avast 5.0462 install on a clean and fully updated Windows 7 Ultimate 64-bit install.

Start -> Run -> msconfig -> General tab -> Diagnostic startup -> reboot - turns close to everything (services, startups, etc.) off. Made sure Windows Firewall is off. Avast 5.x will run in diagnostic startup.

With Avast Web Shield on - Firefox, Chrome, and IE cannot display web pages. Symptoms may include 1) Firefox "Live HTTP Headers" trace remains blank indicating incoming traffic is blocked from the browser; 2) traffic gets through and results in a "Content Encoding Error" indicating the HTTP stream is corrupt; 3) browser times out; 4) you switch back to version 4.8 and 'call it a day'.

Tweaking Web Shield settings to reduce what is going on makes no difference. Turn off Web Shield and all is well except for the new lack of adequate protection for safe se ..urfing.

Here is the HijackThis log - not much running.

Logfile of Trend Micro HijackThis v2.0.2
Scan saved at 10:53:47 PM, on 03/23/10 Tue
Platform: Unknown Windows (WinNT 6.01.3504)
MSIE: Internet Explorer v8.00 (8.00.7600.16385)
Boot mode: Normal

Running processes:
C:\Programs\Security\Avast\AvastUI.exe
C:\Programs\Network\Mozilla Firefox\firefox.exe
C:\PROGRA~2\Java\jre6\bin\jp2launcher.exe
C:\Program Files (x86)\Java\jre6\bin\java.exe
C:\Programs\Security\Trend Micro HijackThis\HijackThis.exe

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://go.microsoft.com/fwlink/?LinkId=69157
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://go.microsoft.com/fwlink/?LinkId=54896
R1 - HKLM\Software\Microsoft\Internet Explorer\Main,Search Page = http://go.microsoft.com/fwlink/?LinkId=54896
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Start Page = http://go.microsoft.com/fwlink/?LinkId=69157
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,SearchAssistant =
R0 - HKLM\Software\Microsoft\Internet Explorer\Search,CustomizeSearch =
R0 - HKLM\Software\Microsoft\Internet Explorer\Main,Local Page = C:\Windows\SysWOW64\blank.htm
R0 - HKCU\Software\Microsoft\Internet Explorer\Toolbar,LinksFolderName =
F2 - REG:system.ini: UserInit=userinit.exe
O2 - BHO: AcroIEHelperStub - {18DF081C-E8AD-4283-A596-FA578C2EBDC3} - C:\Program Files (x86)\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
O2 - BHO: Windows Live Sign-in Helper - {9030D464-4C02-4ABF-8ECC-5164760863C6} - C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live\WindowsLiveLogin.dll
O2 - BHO: LastPass Browser Helper Object - {95D9ECF5-2A4D-4550-BE49-70D42F71296E} - C:\Programs\Security\LastPass\LPBar.dll
O2 - BHO: Java(tm) Plug-In 2 SSV Helper - {DBC80044-A445-435b-BC74-9C25C1C588A9} - C:\Program Files (x86)\Java\jre6\bin\jp2ssv.dll
O3 - Toolbar: LastPass Toolbar - {9f6b5cc3-5c7b-4b5c-97af-19dec1e380e5} - C:\Programs\Security\LastPass\LPBar.dll
O4 - HKUS\S-1-5-20\..\Run: [Sidebar] %ProgramFiles%\Windows Sidebar\Sidebar.exe /autoRun (User '?')
O4 - HKUS\S-1-5-20\..\RunOnce: [mctadmin] C:\Windows\System32\mctadmin.exe (User '?')
O4 - S-1-5-21-4089073572-3114201259-81056830-1001 Startup: AutorunsDisabled (User '?')
O4 - Startup: AutorunsDisabled
O8 - Extra context menu item: LastPass - file://C:\Programs\Security\LastPass\context.html?cmd=lastpass
O8 - Extra context menu item: LastPass Fill Forms - file://C:\Programs\Security\LastPass\context.html?cmd=fillforms
O8 - Extra context menu item: Open Client to monitor &1 - C:\Windows\web\AOpenClient.htm
O8 - Extra context menu item: Open Client to monitor &2 - C:\Windows\web\AOpenClient.htm
O9 - Extra button: Blog This - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra 'Tools' menuitem: &Blog This in Windows Live Writer - {219C3416-8CB2-491a-A3C7-D9FCDDC9D600} - C:\Program Files (x86)\Windows Live\Writer\WriterBrowserExtension.dll
O9 - Extra button: LastPass - {43699cd0-e34f-11de-8a39-0800200c9a66} - C:\Programs\Security\LastPass\LPBar.dll
O13 - Gopher Prefix:
O16 - DPF: {140E4DF8-9E14-4A34-9577-C77561ED7883} (SysInfo Class) - http://content.systemrequirementslab.com.s3.amazonaws.com/global/bin/srldetect_cyri_4.1.71.0.cab
O16 - DPF: {D27CDB6E-AE6D-11CF-96B8-444553540000} (Shockwave Flash Object) - http://fpdownload2.macromedia.com/get/shockwave/cabs/flash/swflash.cab
O17 - HKLM\System\CCS\Services\Tcpip\..\{B2539E19-32D9-4017-BC69-88F12FC361D6}: NameServer = 208.67.222.222,208.67.220.220
O18 - Protocol: skype4com - {FFC8B962-9B40-4DFF-9458-1830C7DD7F5D} - C:\PROGRA~2\COMMON~1\Skype\SKYPE4~1.DLL
O20 - Winlogon Notify: !SASWinLogon - C:\Programs\Security\SUPERAntiSpyware\SASWINLO.dll
O23 - Service: avast! Antivirus - ALWIL Software - C:\Programs\Security\Avast\AvastSvc.exe
O23 - Service: avast! Mail Scanner - ALWIL Software - C:\Programs\Security\Avast\AvastSvc.exe
O23 - Service: avast! Web Scanner - ALWIL Software - C:\Programs\Security\Avast\AvastSvc.exe
O23 - Service: @%SystemRoot%\system32\sppsvc.exe,-101 (sppsvc) - Unknown owner - C:\Windows\system32\sppsvc.exe (file missing)

--
End of file - 4331 bytes

I may switch back to the ever reliable Avast 4.8 until the 5.0 Web Shield is fixed. Of the two, 5.x has the really cool GUI, so that is where I need to be. I vaguely remember a rule that in software, version x.1 is the one to get, not x.0 (whether or not it's software you create) - unless you are Google, in which case beta will do.

Title: Re: webshield blocking web access
Post by: Sp00k on April 15, 2010, 08:06:08 AM
Hi all. Don't know if anyone is still having this issue, but we had exactly the same problem on 2 workstations and fixed it this way:

1. In IE / Firefox etc, enable automatic proxy
2. - In Avast User Interface, click "Settings" (Top right with the spanner icon),
    - Go to "Troubleshooting (on the left column)
    - Expand "Redirect Settings".
       Under "Web" / HTTP port(s):, I had 80.
    - Change this to a different port (for example, I used the default Avast port of 12080
    - Re-open IE or Firefox and (hopefully) you will have Internet access.

I'm not sure why this works. I've checked on computers that have Avast 5 working, and they are set to "80" - and everything still works fine. Either way, it worked for me. Hope it works for someone else as well!
Title: Re: webshield blocking web access
Post by: spg SCOTT on April 15, 2010, 12:35:08 PM
Sp00k,

This is effectively the same as disabling the web scanning of avast! I wouldn't recommend that.

-Scott-