topic Re: File blocking and Google Chrome in General Topics

File blocking and Google Chrome

Chris.Ka — Thu, 25 Jun 2020 09:32:27 GMT

Hi there!

I have the problem that the file blocking no longer works properly at the chrome browser.

The fileblocking profile was configured and appended to the rule, but I can still download msi files. PANOS 9.1.0

Does anyone have suggestions how i can fix this? 🙂

Re: File blocking and Google Chrome

kiwi — Thu, 25 Jun 2020 09:32:08 GMT

Hi @Chris.Ka ,

Is the traffic decrypted correctly ?

Cheers,

-Kiwi.

Re: File blocking and Google Chrome

Chris.Ka — Thu, 25 Jun 2020 09:40:35 GMT

Thanks for your reply.
I think the traffic is decrypted correctly, because the certificate comes from our PA-820.

Re: File blocking and Google Chrome

kiwi — Thu, 25 Jun 2020 11:22:31 GMT

Hi @Chris.Ka ,

Check your traffic sessions to make sure it's being decrypted or not:

https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-admin/decryption/verify-decryption

Anything in the threat log ?

In case the file is identified as another file type you should see it in the threat log thanks to the alert action you have configured ... that said, I'm leaning more towards a decryption issue.

Cheers,

-Kiwi.

Re: File blocking and Google Chrome

Chris.Ka — Mon, 29 Jun 2020 06:34:44 GMT

Hi,

After a few tests I found that the msi file has been successfull blocked...But when I click the retry-button in Chrome Downloads, the rest of the file downloading. Is there a workaround for this?

Re: File blocking and Google Chrome

upelister — Wed, 01 Jul 2020 05:45:56 GMT

Hello,

Chrome sometimes using tricky quick protocol so in firewall appliaction as seen "quick" in firewall logs. Do you have any chance to try this.

For Security Rule;

From a Test host to internet block "quick" so chrome cannot change its behaviour.

For Decryption Rule;

From a test host to internet decrypt all traffic.

*I am using TCP and UDP 443 on decryption policies.

Then analyze log maybe this method can give a clue about why msi file not blocked by firewall.

*before testing be sure, there are no active connection exist from test host to internet, monitor tab>session browser if there is any kill them all.

Have a nice day.

Re: File blocking and Google Chrome

Chris.Ka — Thu, 02 Jul 2020 12:28:11 GMT

Hi,

Quic is already blocked (see screenshot in my first post) and the traffic is decrypted successfully. 😕

My PA-820 doesn't recognize the resume-download as an msi file.

I think this issue has occurred since the update to 9.0 a few months ago.