Attempt to bypass conditional access rule in Microsoft Entra ID

let threshold = 1; // Modify this threshold value to reduce false positives based on your environment
let aadFunc = (tableName:string){
table(tableName)
| where ConditionalAccessStatus == 1 or ConditionalAccessStatus =~ "failure"
| mv-apply CAP = parse_json(ConditionalAccessPolicies) on (
  project ConditionalAccessPoliciesName = CAP.displayName, result = CAP.result
  | where result =~ "failure"
)
| extend DeviceDetail = todynamic(DeviceDetail), Status = todynamic(Status), LocationDetails = todynamic(LocationDetails)
| extend OS = DeviceDetail.operatingSystem, Browser = DeviceDetail.browser
| extend State = tostring(LocationDetails.state), City = tostring(LocationDetails.city), Region = tostring(LocationDetails.countryOrRegion)
| extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails)
// Filter out status codes using watchlist
// uncomment the following line to enable watchlist filtering
// | join kind=leftanti (_GetWatchlist("ConditionalAccessBenignStatusCodes") | project StatusCode) on StatusCode
| extend Status = strcat(StatusCode, ": ", ResultDescription)
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), Status = make_list(Status,10), StatusDetails = make_list(StatusDetails,50), IPAddresses = make_list(IPAddress,100), IPAddressCount = dcount(IPAddress), CorrelationIds = make_list(CorrelationId,100), ConditionalAccessPoliciesName = make_list(ConditionalAccessPoliciesName,100)
by UserPrincipalName, UserId, AppDisplayName, tostring(Browser), tostring(OS), City, State, Region, Type
| where IPAddressCount > threshold and StatusDetails !has "MFA successfully completed"
| mv-expand IPAddresses, Status, StatusDetails, CorrelationIds
| extend Status = strcat(Status, " ", StatusDetails)
| summarize IPAddresses = make_set(IPAddresses,100), Status = make_set(Status,10), CorrelationIds = make_set(CorrelationIds,100), ConditionalAccessPoliciesName = make_set(ConditionalAccessPoliciesName,100)
by StartTime, EndTime, UserPrincipalName, UserId, AppDisplayName, tostring(Browser), tostring(OS), City, State, Region, IPAddressCount, Type
| extend IPAddressFirst = tostring(IPAddresses[0]), Name = tostring(split(UserPrincipalName, "@")[0]), UPNSuffix = tostring(split(UserPrincipalName, "@")[1])
};
let aadSignin = aadFunc("SigninLogs");
let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
union isfuzzy=true aadSignin, aadNonInt

relevantTechniques:
- T1078
- T1098
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: UserPrincipalName
    identifier: FullName
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
- entityType: Account
  fieldMappings:
  - columnName: UserId
    identifier: AadUserId
- entityType: IP
  fieldMappings:
  - columnName: IPAddressFirst
    identifier: Address
version: 1.0.8
id: 3af9285d-bb98-4a35-ad29-5ea39ba0c628
severity: Low
kind: Scheduled
queryFrequency: 1d
description: |
  'Identifies an attempt to Bypass conditional access rule(s) in Microsoft Entra ID.
  The ConditionalAccessStatus column value details if there was an attempt to bypass Conditional Access or if the Conditional access rule was not satisfied (ConditionalAccessStatus == 1).
  References:
  https://docs.microsoft.com/azure/active-directory/conditional-access/overview
  https://docs.microsoft.com/azure/active-directory/reports-monitoring/concept-sign-ins
  https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes
  ConditionalAccessStatus == 0 // Success
  ConditionalAccessStatus == 1 // Failure
  ConditionalAccessStatus == 2 // Not Applied
  ConditionalAccessStatus == 3 // unknown
  Note:
  This analytic rule is designed to identify potential attempts to bypass Conditional Access policies. Depending on your organization's configuration, some Conditional Access failures may be legitimate and expected.
  It is recommended to review alerts generated by this rule in the context of your organization's Conditional Access policies and adjust the detection threshold as needed to reduce false positives.
  This rule includes an optional filter that leverages a watchlist (ConditionalAccessBenignStatusCodes) to exclude known benign status codes. You can customize this watchlist with status codes that are expected in your environment and do not indicate malicious activity.
  By default, the watchlist-based filtering is commented out to provide full visibility into all relevant events. You may choose to enable this filter by uncommenting the corresponding line in the query to reduce noise from known benign scenarios.'  
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - SigninLogs
- connectorId: AzureActiveDirectory
  dataTypes:
  - AADNonInteractiveUserSignInLogs
triggerOperator: gt
name: Attempt to bypass conditional access rule in Microsoft Entra ID
tactics:
- InitialAccess
- Persistence
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/BypassCondAccessRule.yaml
triggerThreshold: 0
queryPeriod: 1d
query: |
  let threshold = 1; // Modify this threshold value to reduce false positives based on your environment
  let aadFunc = (tableName:string){
  table(tableName)
  | where ConditionalAccessStatus == 1 or ConditionalAccessStatus =~ "failure"
  | mv-apply CAP = parse_json(ConditionalAccessPolicies) on (
    project ConditionalAccessPoliciesName = CAP.displayName, result = CAP.result
    | where result =~ "failure"
  )
  | extend DeviceDetail = todynamic(DeviceDetail), Status = todynamic(Status), LocationDetails = todynamic(LocationDetails)
  | extend OS = DeviceDetail.operatingSystem, Browser = DeviceDetail.browser
  | extend State = tostring(LocationDetails.state), City = tostring(LocationDetails.city), Region = tostring(LocationDetails.countryOrRegion)
  | extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails)
  // Filter out status codes using watchlist
  // uncomment the following line to enable watchlist filtering
  // | join kind=leftanti (_GetWatchlist("ConditionalAccessBenignStatusCodes") | project StatusCode) on StatusCode
  | extend Status = strcat(StatusCode, ": ", ResultDescription)
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), Status = make_list(Status,10), StatusDetails = make_list(StatusDetails,50), IPAddresses = make_list(IPAddress,100), IPAddressCount = dcount(IPAddress), CorrelationIds = make_list(CorrelationId,100), ConditionalAccessPoliciesName = make_list(ConditionalAccessPoliciesName,100)
  by UserPrincipalName, UserId, AppDisplayName, tostring(Browser), tostring(OS), City, State, Region, Type
  | where IPAddressCount > threshold and StatusDetails !has "MFA successfully completed"
  | mv-expand IPAddresses, Status, StatusDetails, CorrelationIds
  | extend Status = strcat(Status, " ", StatusDetails)
  | summarize IPAddresses = make_set(IPAddresses,100), Status = make_set(Status,10), CorrelationIds = make_set(CorrelationIds,100), ConditionalAccessPoliciesName = make_set(ConditionalAccessPoliciesName,100)
  by StartTime, EndTime, UserPrincipalName, UserId, AppDisplayName, tostring(Browser), tostring(OS), City, State, Region, IPAddressCount, Type
  | extend IPAddressFirst = tostring(IPAddresses[0]), Name = tostring(split(UserPrincipalName, "@")[0]), UPNSuffix = tostring(split(UserPrincipalName, "@")[1])
  };
  let aadSignin = aadFunc("SigninLogs");
  let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
  union isfuzzy=true aadSignin, aadNonInt  
status: Available