topic Re: Chrome Updater not working if EXE is blocked / application not recognized in General Topics

Chrome Updater not working if EXE is blocked / application not recognized

j.koopmann — Mon, 02 Jul 2012 16:08:24 GMT

Hi,

in one customer setup we face the following problem: We disabled EXE file downloading. In order do allow services to update we use an application filter with subcategory update and allow that traffic. Works like a charm for google-update, ms-update etc. However today I noticed tons of blocks from xxxxxx_Chrome_updater.exe (xxxxx being date, version etc.). The application is "web-browsing". So the update process is not discovered as being an update application. Is this an error or missing feature in the app-id? How can I whitelist this or make a custom application out of this? We see this more often with special EXEs we need to whitelist. Any idea of how to achieve this?

Kind regards,

Re: Chrome Updater not working if EXE is blocked / application not recognized

mikand — Mon, 02 Jul 2012 18:11:46 GMT

1) You posted in wrong subforum - hopefully someone from PA could move your thread so more people will notice it 🙂

2) You can request app enhancement from the Apps and Threats Research Center.

http://www.paloaltonetworks.com/researchcenter/tools/

From there you can click on Submit an app and provide details there.

3) As workaround I think you can do an "application override" if you have something to trigger at. Like:

dsturl: update.google.com

appid: web-browsing

file: .exe

new appid: google-update

Re: Chrome Updater not working if EXE is blocked / application not recognized

j.koopmann — Mon, 02 Jul 2012 19:50:23 GMT

Hi.

ad 1) sorry. which one would have been more suitable? Still have to find my way around Jive I suppose...

ad 2) Done.

ad 3) This is more or less exactly what I want. But I fail to see where/how to do this.

dsturl: update.google.com does not exist. I am trying to figure out which one is the correct URL. I started a pcap and hope that the next request will show the necessary information.

But how do you configure this sort of application override? The ones I know are based on source/destination IP/port not application/file etc. I could create a new application which is based on signatures but how? Where to put the url (request uri?) and how to match on the filename (I would need a regex for that if regex is supported).

Kind regards,

Re: Chrome Updater not working if EXE is blocked / application not recognized

mikand — Mon, 02 Jul 2012 20:24:28 GMT

1) Click on Home in the upper left then on KnowledgePoint and finally Discussion 🙂

3) Oops sorry... application override doesnt act on url. However you can go for dstip (which I guess wont work in this case since its Google we speak about and too many ip's).

Custom application would then be the way to go...

I think something like this might help you:

parent-app: web-browsing

defaults port: tcp/443 (assuming its using https only)

ip protocol: 6 (tcp)

scanning: file-types, data-patterns, viruses

and then the actual signature... check page 171 in the admin guide for examples.

Since this is mainly to allow traffic I think you should be as narrow as you possible can.

Dont forget to have ssl-termination running in order to inspect the https contents.