F-Secure blocks powershell
As of this morning (2020-03-03) we're unable to execute powershell commands on both client workstations and servers.
Even a simple get-childitem returns:
The 'Get-ChildItem' command was found in the module 'Microsoft.PowerShell.Management', but the module could not be loaded.
If we stop the "F-Secure Ultralight Network Hoster" service, the commands executes just right.
Also when we try to execute a PS1-file we get the following error:
"This script contains malicious content and has been blocked by your antivirus software."
Answers
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Can anyone verify this?
Client Security: v14.21
Def: 2020-03-03_02
Server Security: 14.00
Def: 2020-03-03_02
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Same problem here. Does not occur with similar machines without F-Secure installed.
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I have the same issue. Disabling F-Secure resolves the issue so it is F-Secure doing something.
But there is nothing is logged so I can't see what is going on
/Danny
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New update pushed through right now. It works again
/Danny
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Same issue here. Updated Policy Manager from version 14.02 to 14.41 yesterday. Clients using version 14.02 and 14.21.
VBS and Powershell script get blocked without showing any information in F-Secure.
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Yes, same here.
/Klaus
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I can confirm this. New Update fixed it! Thanks.
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Hi,
The false positive detection Trojan-Spy:W32/Powershell_Mimikatz.B that is causing Real-Time scanning to block the Windows PowerShell from being executed, has already been removed and the changes are made by 03-03-2020 09:00 UTC
This detection unintentionally triggered on Windows Powershell and was introduced in the version F-Secure Hydra Update 2020-03-03_01 at 2020-03-03 05:50 UTC.
The fix was released on the following version F-Secure Hydra Update 2020-03-03_02 at 2020-03-03 08:22 UTC.
Regards,
Monika
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