↳ GitHub sourceAnalytics ruleMedium

Brute force attack against an Entra-authenticated Windows device

Description

'Identifies evidence of brute force activity against Windows devices authenticated via Entra ID (including Entra-joined, hybrid-joined, and Windows 365 Cloud PCs) by detecting multiple authentication failures followed by a successful authentication within a defined time window.'
Rule type
Scheduled
Version
2.0.3
Declared status
Available
Query frequency
1d
Query period
1d
Trigger
gt 0

Declared MITRE coverage

Declared sources

Metadata from the source file. No dependencies inferred from KQL.

Connectors

Data types

KQL query

Original query, unchanged.

let authenticationWindow = 20m;
let sensitivity = 2.5;
SigninLogs
| where AppDisplayName =~ "Windows Sign In"
| extend FailureOrSuccess = iff(ResultType in ("0", "50125", "50140", "70043", "70044"), "Success", "Failure")
| summarize FailureCount = countif(FailureOrSuccess=="Failure"), SuccessCount = countif(FailureOrSuccess=="Success"), IPAddresses = make_set(IPAddress,1000)
                          by bin(TimeGenerated, authenticationWindow), UserDisplayName, UserPrincipalName
| extend FailureSuccessDiff = FailureCount - SuccessCount
| where FailureSuccessDiff > 0
| sort by UserPrincipalName asc, TimeGenerated asc
| serialize
| summarize Diff = make_list(FailureSuccessDiff, 10000), TimeStamp = make_list(TimeGenerated, 10000) by UserDisplayName, UserPrincipalName//, tostring(IPAddresses)
| extend (Anomalies, Score, Baseline) = series_decompose_anomalies(Diff, sensitivity, -1, 'linefit')  
| mv-expand Diff to typeof(double), TimeStamp to typeof(datetime), Anomalies to typeof(double), Score to typeof(double), Baseline to typeof(long)
| where Anomalies > 0
| summarize by UserDisplayName, UserPrincipalName, Anomalies, Score, Baseline, FailureToSuccessDiff = Diff
| join kind=leftouter (
      SigninLogs
      | where AppDisplayName =~ "Windows Sign In"
      | extend OS = DeviceDetail.operatingSystem, Browser = DeviceDetail.browser
      | extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails)
      | extend State = tostring(LocationDetails.state), City = tostring(LocationDetails.city)
      | summarize StartTime = min(TimeGenerated), 
                  EndTime = max(TimeGenerated), 
                  IPAddresses = make_set(IPAddress,100), 
                  OS = make_set(OS,20), 
                  Browser = make_set(Browser,20), 
                  City = make_set(City,100), 
                  ResultType = make_set(ResultType,100)
              by UserDisplayName, UserPrincipalName, UserId, AppDisplayName
  ) on UserDisplayName, UserPrincipalName
| project-away UserDisplayName1, UserPrincipalName1
| extend IPAddressFirst = tostring(IPAddresses[0])
| extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])

Declared entities

AccountIP

Related content

Links established from declared identifiers and solution manifests.

Source provenance

GitHub

Displayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.

Source identifier
3fbc20a4-04c4-464e-8fcb-6667f53e4987
Additional source files 2Solutions/Microsoft Entra ID/Analytic Rules/BruteForceAgainstanEntraAuthenticatedWindowsDevice.yamlsource ↗Solutions/Microsoft Entra ID/Data/Solution_AAD.jsonsolution-membership ↗
GSTEP / CATALOG TRACKING

Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC

GSTEP sync dates, separate from the source content’s publication dates.