Block all downloads

[Boyet728]

Hello everyone. I would like to know if there is a way I can block all downloads from the internet base on file extension using EndPoint Security. I looked into Web Control but this seem to be dependent on GTI ratings, which does not solve my issue. I saw one suggestion to use Access Protection but this may not work cause what I am trying to block is exe, msi, bat, or zips downloaded by any browser but the user can bypass this option and save to any location and launch, or either defining it as PUP because PUP Is triggered from OAS or ODS.

Any advise would be greatly appreciated. 

[Tares1 · Accepted solution]

Hello @Boyet728 

Thank you for reaching out to the support community.

As you said it can't be blocked by webcontrol as it is dependant on GTI ratings.

And access protection rules would apply to either specific folders or all the systems and would impact all files with those extensions, instead of just those downloaded from the web.

Another option would be to create your own exploit prevention rule to block those contents that come through specific browser processes, but that would have to be quite specific and have a high risk of causing other unpredictable impacts on your systems, so testing any of those changes in a test environment is advisable.

Having those executables designed as PUP would not solve your issue as they need to meet certain criteria for that and not all can be accepted as a PUP into the DAT, if you know which files specifically you want to block then the access protection rule is your best option, but then again, it is advisable to test thoroughly before deploying o your environment.

Hope this helps answer your query.

[Boyet728]

I was able to block any downloads base on file extension like you described, solution was to create an expert rule for exploit prevention including objects as the browsers and target the files extensions that are executables that tries to create. Code below in case anyone needs it or can improve on it:

Rule {
   Process {
        Include OBJECT_NAME {
          -v chrome.exe
          -v msedge.exe
          -v firefox.exe
          -v iexplore.exe
        }
    }
        Target {
           Match FILE {
           Include OBJECT_NAME {
                -v "*.exe"
                -v "*.msi"
                -v "*.ps1"
                -v "*.bat"
                -v "*.com"
                -v "*.wsf"
                -v "*.vbs"
                -v "*.dll"
                -v "*.run"
         }
         Include -access "CREATE"
      }
   }
}

[mtmy-zul]

Hi, 

How do I apply this code please?

[Pravas]

Hi @mtmy-zul ,

Please follow the instructions from KB link below. Replace code in 7d with the one mentioned by @Boyet728 

https://kc.mcafee.com/corporate/index?page=content&id=KB92752

Also please test the rule before applying to all systems.

Thanks

[mtmy-zul]

It worked. thanks. 

Does this will effect windows update download if they used the same file extension that I have blocked?

[Pravas]

Hi @mtmy-zul ,

I'm glad to hear it works. 

It shouldn't have any affect on windows update as long as the source process is Not 

chrome.exe
msedge.exe
firefox.exe
iexplore.exe

Thanks