Attached images and PDF files in emails get corrupted when protocol filtering is ON

[IB005 0]

Many images and PDF files attached to my incoming emails get corrupted. The same happens with PDF files I try to download from the web.

I had a similar problem last year, and the only way I found to fix it then was disabling SSL/TLS under protocolo filtering in ESET.

Now it started to happen again (SSL/TLS is still disabled) and the only way I find to download those types of files correctly is disabling Protocol filtering completely. This prompts a security alert in ESET that urges me to activate that feature.

I do not want to have a security feature disabled, but I do want to be able to receive and download images and PDF files correctly.

Please any advice on how to solve this problem?

 

[Marcos 5,070]

Are you able to open this pdf ? https://www.eset.com/fileadmin/ESET/US/resources/datasheets/ESETus-B2B-SO-WEB.pdf

I didn't have any issues while having protocol filtering enabled so maybe you have another software possibly clashing with ESET installed. Please provide logs collected with ESET Log Collector.

[itman 1,659]

1 hour ago, Marcos said:

Are you able to open this pdf ? https://www.eset.com/fileadmin/ESET/US/resources/datasheets/ESETus-B2B-SO-WEB.pdf

No problem opening this in Firefox. Note I have Firefox configured to use its internal PDF reader to open .pdf files.

Next, I downloaded the .pdf and attached it to a new e-mail using Thunderbird e-mail client. Then I e-mailed it to myself. When the e-mail arrived in my In Box, I opened it this time using Abobe Reader. Again, no issues with .pdf corruption or viewing the .pdf.

2 hours ago, IB005 said:

The same happens with PDF files I try to download from the web.

What browser are you using to download these files? I really appears to me that is where the issue exists. I also assume you are using web based e-mail and not an e-mail client?

[IB005 0]

On 10/21/2020 at 8:16 AM, Marcos said:

Are you able to open this pdf ? https://www.eset.com/fileadmin/ESET/US/resources/datasheets/ESETus-B2B-SO-WEB.pdf

I didn't have any issues while having protocol filtering enabled so maybe you have another software possibly clashing with ESET installed. Please provide logs collected with ESET Log Collector.

 

On 10/21/2020 at 10:11 AM, itman said:

No problem opening this in Firefox. Note I have Firefox configured to use its internal PDF reader to open .pdf files.

Next, I downloaded the .pdf and attached it to a new e-mail using Thunderbird e-mail client. Then I e-mailed it to myself. When the e-mail arrived in my In Box, I opened it this time using Abobe Reader. Again, no issues with .pdf corruption or viewing the .pdf.

What browser are you using to download these files? I really appears to me that is where the issue exists. I also assume you are using web based e-mail and not an e-mail client?

 

Thanks for replying Marcos and itman.

@Marcos I was able to open that pdf with protocol filtering off, and also on. But I still get most other downloads and email attachments corrupted when protocol filtering is on.

@itman For browsing I use both Chrome and Firefox. For emails I use Windows Live Mail and MS Outlook. The same problem occurs with all of them. So I think it might not be caused by the browser or email client.

Also, when I turn protocol filtering off I never have problems with any download or attachment. Maybe there's some incompatibility between this function and something in my system?

Note that I hadn't had this issue since I disabled SSL/TLS filtering in ESET last year, until a few days ago. Seems like some recent update to ESET could have caused this issue reappear?

@Marcos I will get the logs and post them.

 

[Marcos 5,070]

Please provide the url to a pdf file which is corrupted when downloaded with protocol filtering enabled.

[itman 1,659]

3 hours ago, Marcos said:

Please provide the url to a pdf file which is corrupted when downloaded with protocol filtering enabled.

The OP stated the problem exists with .pdf e-mail attachments.

[IB005 0]

1 hour ago, itman said:

The OP stated the problem exists with .pdf e-mail attachments.

That's right, most files in attachments (even images and documents) get corrupted. Same thing with files downloaded from the web.

If I try to download again the same file, the corruption might not be the same. For example, different number of pages are missing or corrupted (generally the first page is partially corrupted and the following pages are blank).

 

[LesRMed 22]

1 minute ago, IB005 said:

If I try to download again the same file, the corruption might not be the same. For example, different number of pages are missing or corrupted (generally the first page is partially corrupted and the following pages are blank).

I've seen that before with a corrupt or bad video card driver. 

[itman 1,659]

3 minutes ago, IB005 said:

If I try to download again the same file, the corruption might not be the same. For example, different number of pages are missing or corrupted (generally the first page is partially corrupted and the following pages are blank).

These are direct web page based downloads and not from a public file sharing site?

[IB005 0]

17 minutes ago, LesRMed said:

I've seen that before with a corrupt or bad video card driver. 

In my case it never happens when Protocol filtering is disabled. Could ESET be interfering with downloads because of a corrupt video driver?

 

[IB005 0]

23 minutes ago, itman said:

These are direct web page based downloads and not from a public file sharing site?

They were direct web page downloads. I haven't tried from file sharing sites.

[itman 1,659]

Are you using a proxy?