Author Topic: Web Shield seems to be corrupting downloads - Avast free 5.1.889  (Read 11708 times)

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hake

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Web Shield seems to be corrupting downloads - Avast free 5.1.889

When I stop Web Shield, downloads are not corrupted.  The problem seems to apply to .exe files.  Downloaded installation files have been failing MD5 or are crashing when run.  When I restart Web Shield, the problem returns.

The curious thing is that general internet traffic seems unaffected or at least no errors are apparent.  This problem exists on all four of my Windows XP Pro SP3 systems.

Offline schmidthouse

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #1 on: January 15, 2011, 11:29:12 PM »
Web Shield seems to be corrupting downloads - Avast free 5.1.889

When I stop Web Shield, downloads are not corrupted.  The problem seems to apply to .exe files.  Downloaded installation files have been failing MD5 or are crashing when run.  When I restart Web Shield, the problem returns.

The curious thing is that general INTERNET traffic seems unaffected or at least no errors are apparent.  This problem exists on all four of my Windows XP Pro SP3 systems.

Hello hake: This seems extremely peculiar that you would have the exact same (Avast??) issue on all 4 machines.
Have you tried an uninstall and 'Clean install' of Avast on one of your machines and see if anything changes on that machine?
As you can see from my signature I run Avast Pro on both my machines and have never seen an issue like this. As a matter of fact, I've never had a download of executables and Web Shield issue ever. ???

Offline igor

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #2 on: January 15, 2011, 11:39:34 PM »
Can you give us an example of the URLs you were downloading from?
If you download the same file repeatedly, does it always give the same result for you, or is it random?
Did you try to compare (e.g. the hash of) the file downloaded with and without the Web Shield?

hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #3 on: January 16, 2011, 01:04:02 AM »
I have done as requested and reinstalled by uninstalling then using aswclear5.exe then finally giving the registry a clean with cclean and PC Tools Registry Mechanic.  I then did a clean install using Avast 5 free setup_av_free.exe (v5.1.889).

The problem remains.  It is late and I must sleep.  I had no problem with v5.0.677.  I have only become aware of a problem since v5.1.889 but cannot be absolutely certain that it did not exist with v5.1.864.  I was first aware that something was amiss when I tried to do the weekly update of Spybot - Search and Destroy last Wednesday (January 12) and wondered why I could not download good updates.

So far, I am only aware of .exe files being affected.

I can try reverting to v5.1.864 tomorrow.

Offline igor

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #4 on: January 16, 2011, 01:22:31 AM »
Version 5.1.864 contained some problems, it's certainly not what you want to revert to.
Could you please answer my questions? (when you have a while)
« Last Edit: January 16, 2011, 01:25:25 AM by igor »

hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #5 on: January 16, 2011, 01:31:11 AM »
Problem also occurs with v5.1.864.  I intend to revert to v5.0.677, the use of which did not coincide with this problem.

Offline DavidR

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #6 on: January 16, 2011, 02:10:18 AM »
Igor, one of the avast developers is trying to help you (after all that is why you came to the forums) so that you can use avast 5.1, which is better than avast 5.0.

So answering his questions helps him to see if there is a fault/bug that can be rectified and may also help others.
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hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #7 on: January 16, 2011, 02:16:07 AM »
Yes, I realise that.  I am struggling with incompatibility between latest database updates and v5.0.677.  Database update proclaimed to have invalid file.  Looks like I cannot revert.

It's one o'clock in the morning.  I am tired and need to sleep so my head works properly.  The evidence I am trying to gather is sparse and inconsistent.
« Last Edit: January 16, 2011, 02:22:02 AM by hake »

hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #8 on: January 16, 2011, 11:30:50 AM »
Thanks for looking at this Igor.  Sorry I didn't supply more help last night at 0100 hours.

Example download 'detection updates' (filename: spybotsd_includes.exe)
from URL http://www.safer-networking.org/en/download/index.html

I get a different MD5 hash for each copy downloaded when Web Shield is ON.  I have seen correct MD5 hash when Web Shield is ON but it rarely happens.

When Web Shield is OFF, MD5 hash is the same for each copy of the file.

The problem seems to be general to any downloaded .exe file.  I have not noticed if any other file type is also affected.

I am running a fully patched Windows XP Pro SP3.  I use Agnitum Outpost Firewall Pro 7.0.4 (3412.520.1245).  There is no other real time security software.  Avast File System Shield is set to exclude the Agnitum folder in Program Files.  All other installed security software is for on-demand scanning only.

Oops!  I forgot to say that I also use Trusteer Rapport (build 1005.71) and that the problem persists even  when Agnitum Outpost Firewall Pro Web Control feature is disabled.

I do my best to supply further information.
« Last Edit: January 16, 2011, 12:54:09 PM by hake »

Hermite15

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #9 on: January 16, 2011, 12:58:13 PM »
yep that's a weird and interesting issue... never saw that happen but I want to follow the topic.

Hermite15

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #10 on: January 16, 2011, 01:04:20 PM »
just checked with SS&D download and web shield on, sorry man but MD5 matches here, see screen shots
« Last Edit: January 16, 2011, 01:06:45 PM by Logos »

hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #11 on: January 16, 2011, 01:25:16 PM »
That is not the MD5 hash shown on http://www.safer-networking.org/en/download/index.html which is '4F993A9A08BC97C0BCEBE99592FD033F'.

The important thing for me is that I am now aware of a problem so I can anticipate and work round it when I need to download a .exe file.  I was puzzled for a few days when downloaded .exe files would not execute.  Some downloads do work, for instance the very recent Google Chrome update worked fine so, presumably, not all downloads pass through Web Shield / port 12080.

In spite of this, I am very pleased with Avast v5.1.889.  The improvements to Behaviour Shield are especially welcome since Threatfire appears to be dead in the water (Threatfire has been removed from my systems).
« Last Edit: January 16, 2011, 01:36:18 PM by hake »

Hermite15

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #12 on: January 16, 2011, 01:32:14 PM »
That is not the MD5 hash shown on http://www.safer-networking.org/en/download/index.html which is '4F993A9A08BC97C0BCEBE99592FD033F'.

you must be kidding me, I'm talking about s&d.exe, and again as shown on the page and reported on my screen shot above MD5 matches perfectly.

 Your referred to MD5 is a database update, and I didn't test that ::) ... but now I did, and it matches too  ;D ... sounds like you got a bit mixed up didn't you :)

hake

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #13 on: January 16, 2011, 01:41:49 PM »
I was talking about Detection updates (I clearly stated this), not the product installation package.  Can you please check MD5 hash on detection updates for 12 January (filename: spybotsd_includes.exe).  The MD5 hash '4F993A9A08BC97C0BCEBE99592FD033F' is for that.

Hermite15

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Re: Web Shield seems to be corrupting downloads - Avast free 5.1.889
« Reply #14 on: January 16, 2011, 01:42:48 PM »
I was talking about Detection updates (I clearly stated this), not the product installation package.  Can you please check MD5 hash on detection updates for 12 January (filename: spybotsd_includes.exe).  The MD5 hash '4F993A9A08BC97C0BCEBE99592FD033F' is for that.

jesus christ I just did!!!  ::) ... if you read MD5's as carefully as you read posts here we got a problem.