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MediumMicrosoft Sentinel analyticsMicrosoft Security Research

High count of failed logons by a user

Identifies when 100 or more failed attempts by a given user in 10 minutes occur on the IIS Server. This could be indicative of attempted brute force based on known account information. This could also simply indicate…

Description

Identifies when 100 or more failed attempts by a given user in 10 minutes occur on the IIS Server. This could be indicative of attempted brute force based on known account information. This could also simply indicate a misconfigured service or device. References: IIS status code mapping - https://support.microsoft.com/help/943891/the-http-status-code-in-iis-7-0-iis-7-5-and-iis-8-0 Win32 Status code mapping - https://msdn.microsoft.com/library/cc231199.aspx

Detection logic

Detection requirements

Platform
ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source product
azuremonitor_iis
Log source service
w3ciislog

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