File blocking and Google Chrome

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L1 Bithead

File blocking and Google Chrome

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

 

profile.png

 

 

rule.png

 

download.png

Does anyone have suggestions how i can fix this?

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Community Team Member

Hi @Chris.Ka ,

 

Is the traffic decrypted correctly ?

 

Cheers,

-Kiwi.

 
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L1 Bithead

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

cert.png

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Community Team Member

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.

 
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L1 Bithead

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?

download_failed.png download_ok.pngDatafiltering.png

traffic_log_detail.png

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L2 Linker

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.

UP
L1 Bithead

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.

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