Sandbox false positive .NET 6.0.1 & 7.0.5 Update

Dexta · April 2023

It seems, that the sandbox has a false positive on the windows update for the .net applications once again.

SUSPICIOUS infected SSI:N File:dotnet-runtime-6.0.16-win-x64_9525ba632a628128ec7113ac9d34fe1c2 Protocol:HTTP

Hash Value: 5a44d8accd7e7ed333940f4600919f53

SUSPICIOUS infected SSI:N File:windowsdesktop-runtime-7.0.5-win-x64_5b4232eed009e6b66c64a6096b Protocol:HTTP

Hash Value: 13395bd3897467c7f9f9303d197e70fd

Is there no way to whitelist certain files or URL's?

Kind regards,

Michael

jurusam · April 2023

Me too…
… and >600 emails with CDR !!!!

#	File name	hash	Type	Occurences	Update time
1	windowsdesktop-runtime-6.0.16-win-x64_b5158efdf04bc521d4d4f0618	5107b5f5a31e086796446ed3df572838	Suspicious	194	2023-04-12 09:59
2	dotnet-runtime-6.0.16-win-x64_9525ba632a628128ec7113ac9d34fe1c2	5a44d8accd7e7ed333940f4600919f53	Suspicious	340	2023-04-12 08:48
3	aspnetcore-runtime-6.0.16-win-x64_3f06ad4f7609c3ecf37803e7576be	e54dd2b8961f1673896c7ce106bd91ae	Suspicious	28	2023-04-12 08:32
4	dotnet-hosting-7.0.5-win_c12bb335682504f51512e4434bb7fda331a0cc	e1cb42132192939ae486b3758462738c	Suspicious	1	2023-04-12 07:30
5	windowsdesktop-runtime-7.0.5-win-x64_5b4232eed009e6b66c64a6096b	13395bd3897467c7f9f9303d197e70fd	Suspicious	1	2023-04-12 07:30
6	aspnetcore-runtime-7.0.5-win-x64_bd5b7e737025d237bec869f71c97df	c9175d4d5c24892631c4e6c228403172	Suspicious	1	2023-04-12 07:30

Zyxel_Jeff · April 2023

Hi @Dexta and @jurusam

Thanks for reporting this case to us. Please add the issued hash value to Anti-Malware's allow list now. You can refer to this FAQ article for guidance. We will check those false positive detection cases internally, I will keep updating this discussion.

https://community.zyxel.com/en/discussion/15174/how-to-resolve-anti-malware-and-sandboxing-false-positive-case

Dexta · April 2023

Dear @Zyxel_Jeff

Thanks for the fast reply. I assume it works the same for on Nebula?

This happens after every patchday from microsoft with the .net-Update. Isn't it possible for you to update your database after every patchday?

Kind regards,

Michael

USG_User · April 2023

The problem is that it will reappear again and again on each MS patchday since the .NET or Windows desktop runtimes change its release numbers (and connected hash values) very often. It is no solution to let the user adding any hash values to the "allow list" subsequently every time.

We encountered this behaviour also for months. Fortunately it's gone with us since we have upgraded from our old USG110 to an USG Flex 700. But other user still report about this issue also with an USG Flex. Don't know what it depends on.

mMontana · April 2023

The "sometimes" seems such more "every update pulled by Microsoft".

Zyxel_Jeff · April 2023

https://community.zyxel.com/en/discussion/comment/50789#Comment_50789

Hi @Dexta

The Nebula firewall may also experience this phenomenon. A temporary workaround solution is to add the file pattern to the allow list and inform us of any false positive detections. Thanks.

Dexta · April 2023

Hi @Zyxel_Jeff

Thanks for the help. Are there any plans to update the database on windowspatch day? I does not make sense for the users to report these false positives because they are going to happen on every patchday.

Kind regards,
Michael

Zyxel_Jeff · April 2023

Hi @Dexta and @jurusam

May we know what USG Flex or ATP series model you are using? Did this false positive detection appear on Sandboxing only or on Anti-Malware as well? If so, what is your signature version of Antil-Malware? What is the Scan Mode for Anti-Malware? Is it Express Mode, Stream Mode, or Hybrid Mode? Could you share screenshots of the setting page and historical Monitor Log messages of false positive detection with us? It's easier for us to check your situation.

Anti-Malware setting page example:

Sandboxing setting page example:

Thank you!

Dexta · April 2023

Dear @Zyxel_Jeff

We are using ATP500 and it's only the sandboxing. Attached you find the screenshots.
Settings:

Report from the week of the MS patch day in february:

Secureporter History from MS Patch day this month:

I did not include the Report from the March Patch day because the new weekly report from SecuReporter does not show the hash values anymore and in the reporter it self we can go back by maximum 30 days.

Zyxel_Jeff · April 2023

Hi @Dexta

Thanks for sharing the helpful information with us.

Sandbox false positive .NET 6.0.1 & 7.0.5 Update

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