List of any firewall and antivirus software blocking Blazor WebAssembly applications

[mkArtakMSFT]

We've learned about customers who have been seeing issues with their Blazor WebAssembly applications being blocked by either Firewall or Anti-virus software.
We're going to use this issue to build up the list of such software which interferes with Blazor WebAssembly so that we can follow up with their providers and try to address those issues.

ASK

If you have observed (first hand) a situation like the one described above, please comment below the details of the software which has blocked your application in the following format:

**Software name**: My custom antivirus
**Version**: 7.7
**Website**: https://MyCustomAntiVirus.com
**Context**: Any relevant information, which is specific to this scenario.

Note

Please note that this issue should not be used for discussions, rather simply a way to build up the list. The discussion issue for this topic is: #5477
Comments, which do not comply with this format will be removed.

[mrpmorris]

We are using a Palo Alto firewall.

The console is filled with errors like this

HTTP503: SERVICE UNAVAILABLE - The service is temporarily overloaded
(XHR)GET - http://(redacted).azurewebsites.net/_framework/_bin/(redacted).Components.Dismissable.dll

In Firefox 73.0.1 the DLL requests appear in the Network tab with 503 statuses.
In Chrome 80.0.3987.122 the Network response is ERR_CONNECTION_RESET.

Using https:// fixes the problem for me, I expect this could be the firewall trusting the content because it knows it hasn't been modified en-route.

[spottedmahn]

Software name: sophos web protection
Version: version of what? sophos?
Website: http://opensilvershowcase.azurewebsites.net
Context:

http://opensilvershowcase.azurewebsites.net/_framework/_bin/System.ComponentModel.DataAnnotations.dll

[mihaimyh]

Hi,

My corporate antivirus blocks all .dll downloaded in Chrome or other browsers:

Reputation: Unverified
Media Type: application/executable, application/dotnet-assembly
Rule Set name: Block Access to Site/IP & Alert Notification
Rule name: exe Block By Media Type
generated 2020-04-03 10:33:24 by McAfee Web Gateway

[zeeshanejaz]

Software name: Avast Antivirus
Version: 20.1.2397 (build 20.1.5069.562)
Website: https://avast.com
Context: Blazor webassembly apps are blocked with an error message "We have safely aborted connected with https://website.com because it was infected with DRep". Investigating this error has lead to a "domain reputation" issue. Since my domain is new and is not used by many people, it is considered of low reputation. This means I am unable to user Blazor webassembly for new projects.

[mkArtakMSFT]

Thanks everyone.
It seems that the only actual antivirus which is causing a problem is Avast. All the other reported cases are firewall specific, which seem to be caused by the fact that Blazor libraries are .dll files. We have a resolution to this already in the original thread here: #5477 (comment)
In parallel, we're going to work with Avast antivirus software vendors offline to get this resolved.
Given that there is no more pending action here, I'm closing this issue.

[spottedmahn]

We have a resolution to this already in the original thread

Any chance you can link to that specific comment? thanks!

[mrpmorris]

@spottedmahn some suggestions here #5477

[zeeshanejaz]

I think it's a good idea to test all popular antivirus AVG, NOD32, MalwareBytes, Avira, Kaspersky, Norton, Macfee, etc.

[spottedmahn]

some suggestions here #5477

Hi @mrpmorris - I know 😉 but the thread is super long. Very tedious to find the comment(s) w/ the workarounds. Not very stackoverflow-ish if you will 😊

[mkArtakMSFT]

Here is the comment: #5477 (comment)

[spottedmahn]

thanks @mkArtakMSFT! 🤝