Sign-ins from IPs that attempt sign-ins to disabled accounts

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Id	500c103a-0319-4d56-8e99-3cec8d860757
Rulename	Sign-ins from IPs that attempt sign-ins to disabled accounts
Description	Identifies IPs with failed attempts to sign in to one or more disabled accounts using the IP through which successful signins from other accounts have happened. This could indicate an attacker who obtained credentials for a list of accounts and is attempting to login with those accounts, some of which may have already been disabled. References: https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes 50057 - User account is disabled. The account has been disabled by an administrator. This query has also been updated to include UEBA logs IdentityInfo and BehaviorAnalytics for contextual information around the results.
Severity	Medium
Tactics	InitialAccess Persistence
Techniques	T1078 T1098
Required data connectors	AzureActiveDirectory BehaviorAnalytics
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/SigninAttemptsByIPviaDisabledAccounts.yaml
Version	2.1.3
Arm template	500c103a-0319-4d56-8e99-3cec8d860757.json

KQL

let aadFunc = (tableName: string) {
let failed_signins = table(tableName)
| where ResultType == "50057"
| where ResultDescription == "User account is disabled. The account has been disabled by an administrator.";
let disabled_users = failed_signins | summarize by UserPrincipalName;
table(tableName)
  | where ResultType == 0
  | where isnotempty(UserPrincipalName)
  | where UserPrincipalName !in (disabled_users)
| summarize
        successfulAccountsTargettedCount = dcount(UserPrincipalName),
        successfulAccountSigninSet = make_set(UserPrincipalName, 100),
        successfulApplicationSet = make_set(AppDisplayName, 100)
    by IPAddress, Type
    // Assume IPs associated with sign-ins from 100+ distinct user accounts are safe
    | where successfulAccountsTargettedCount < 50
    | where isnotempty(successfulAccountsTargettedCount)
  | join kind=inner (failed_signins
| summarize
    StartTime = min(TimeGenerated),
    EndTime = max(TimeGenerated),
    totalDisabledAccountLoginAttempts = count(),
    disabledAccountsTargettedCount = dcount(UserPrincipalName),
    applicationsTargeted = dcount(AppDisplayName),
    disabledAccountSet = make_set(UserPrincipalName, 100),
    disabledApplicationSet = make_set(AppDisplayName, 100)
by IPAddress, Type
| order by totalDisabledAccountLoginAttempts desc) on IPAddress
| project StartTime, EndTime, IPAddress, totalDisabledAccountLoginAttempts, disabledAccountsTargettedCount, disabledAccountSet, disabledApplicationSet, successfulApplicationSet, successfulAccountsTargettedCount, successfulAccountSigninSet, Type
| order by totalDisabledAccountLoginAttempts};
let aadSignin = aadFunc("SigninLogs");
let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
union isfuzzy=true aadSignin, aadNonInt
| join kind=leftouter (
    BehaviorAnalytics
    | where ActivityType in ("FailedLogOn", "LogOn")
    | where EventSource =~ "Azure AD"
    | project UsersInsights, DevicesInsights, ActivityInsights, InvestigationPriority, SourceIPAddress, UserPrincipalName
    | project-rename IPAddress = SourceIPAddress
    | summarize
        Users = make_set(UserPrincipalName, 100),
        UsersInsights = make_set(UsersInsights, 100),
        DevicesInsights = make_set(DevicesInsights, 100),
        IPInvestigationPriority = sum(InvestigationPriority)
    by IPAddress
) on IPAddress
| extend SFRatio = toreal(toreal(disabledAccountsTargettedCount)/toreal(successfulAccountsTargettedCount))
| where SFRatio >= 0.5
| sort by IPInvestigationPriority desc

YAML

requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - SigninLogs
- connectorId: AzureActiveDirectory
  dataTypes:
  - AADNonInteractiveUserSignInLogs
- connectorId: BehaviorAnalytics
  dataTypes:
  - BehaviorAnalytics
triggerOperator: gt
queryFrequency: 1d
name: Sign-ins from IPs that attempt sign-ins to disabled accounts
queryPeriod: 1d
id: 500c103a-0319-4d56-8e99-3cec8d860757
description: |
  'Identifies IPs with failed attempts to sign in to one or more disabled accounts using the IP through which successful signins from other accounts have happened.
  This could indicate an attacker who obtained credentials for a list of accounts and is attempting to login with those accounts, some of which may have already been disabled.
  References: https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes
  50057 - User account is disabled. The account has been disabled by an administrator.
  This query has also been updated to include UEBA logs IdentityInfo and BehaviorAnalytics for contextual information around the results.'  
severity: Medium
query: |
  let aadFunc = (tableName: string) {
  let failed_signins = table(tableName)
  | where ResultType == "50057"
  | where ResultDescription == "User account is disabled. The account has been disabled by an administrator.";
  let disabled_users = failed_signins | summarize by UserPrincipalName;
  table(tableName)
    | where ResultType == 0
    | where isnotempty(UserPrincipalName)
    | where UserPrincipalName !in (disabled_users)
  | summarize
          successfulAccountsTargettedCount = dcount(UserPrincipalName),
          successfulAccountSigninSet = make_set(UserPrincipalName, 100),
          successfulApplicationSet = make_set(AppDisplayName, 100)
      by IPAddress, Type
      // Assume IPs associated with sign-ins from 100+ distinct user accounts are safe
      | where successfulAccountsTargettedCount < 50
      | where isnotempty(successfulAccountsTargettedCount)
    | join kind=inner (failed_signins
  | summarize
      StartTime = min(TimeGenerated),
      EndTime = max(TimeGenerated),
      totalDisabledAccountLoginAttempts = count(),
      disabledAccountsTargettedCount = dcount(UserPrincipalName),
      applicationsTargeted = dcount(AppDisplayName),
      disabledAccountSet = make_set(UserPrincipalName, 100),
      disabledApplicationSet = make_set(AppDisplayName, 100)
  by IPAddress, Type
  | order by totalDisabledAccountLoginAttempts desc) on IPAddress
  | project StartTime, EndTime, IPAddress, totalDisabledAccountLoginAttempts, disabledAccountsTargettedCount, disabledAccountSet, disabledApplicationSet, successfulApplicationSet, successfulAccountsTargettedCount, successfulAccountSigninSet, Type
  | order by totalDisabledAccountLoginAttempts};
  let aadSignin = aadFunc("SigninLogs");
  let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
  union isfuzzy=true aadSignin, aadNonInt
  | join kind=leftouter (
      BehaviorAnalytics
      | where ActivityType in ("FailedLogOn", "LogOn")
      | where EventSource =~ "Azure AD"
      | project UsersInsights, DevicesInsights, ActivityInsights, InvestigationPriority, SourceIPAddress, UserPrincipalName
      | project-rename IPAddress = SourceIPAddress
      | summarize
          Users = make_set(UserPrincipalName, 100),
          UsersInsights = make_set(UsersInsights, 100),
          DevicesInsights = make_set(DevicesInsights, 100),
          IPInvestigationPriority = sum(InvestigationPriority)
      by IPAddress
  ) on IPAddress
  | extend SFRatio = toreal(toreal(disabledAccountsTargettedCount)/toreal(successfulAccountsTargettedCount))
  | where SFRatio >= 0.5
  | sort by IPInvestigationPriority desc  
triggerThreshold: 0
version: 2.1.3
kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/SigninAttemptsByIPviaDisabledAccounts.yaml
entityMappings:
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: IPAddress
relevantTechniques:
- T1078
- T1098
tactics:
- InitialAccess
- Persistence
status: Available

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/500c103a-0319-4d56-8e99-3cec8d860757')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/500c103a-0319-4d56-8e99-3cec8d860757')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "Sign-ins from IPs that attempt sign-ins to disabled accounts",
        "description": "'Identifies IPs with failed attempts to sign in to one or more disabled accounts using the IP through which successful signins from other accounts have happened.\nThis could indicate an attacker who obtained credentials for a list of accounts and is attempting to login with those accounts, some of which may have already been disabled.\nReferences: https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes\n50057 - User account is disabled. The account has been disabled by an administrator.\nThis query has also been updated to include UEBA logs IdentityInfo and BehaviorAnalytics for contextual information around the results.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let aadFunc = (tableName: string) {\nlet failed_signins = table(tableName)\n| where ResultType == \"50057\"\n| where ResultDescription == \"User account is disabled. The account has been disabled by an administrator.\";\nlet disabled_users = failed_signins | summarize by UserPrincipalName;\ntable(tableName)\n  | where ResultType == 0\n  | where isnotempty(UserPrincipalName)\n  | where UserPrincipalName !in (disabled_users)\n| summarize\n        successfulAccountsTargettedCount = dcount(UserPrincipalName),\n        successfulAccountSigninSet = make_set(UserPrincipalName, 100),\n        successfulApplicationSet = make_set(AppDisplayName, 100)\n    by IPAddress, Type\n    // Assume IPs associated with sign-ins from 100+ distinct user accounts are safe\n    | where successfulAccountsTargettedCount < 50\n    | where isnotempty(successfulAccountsTargettedCount)\n  | join kind=inner (failed_signins\n| summarize\n    StartTime = min(TimeGenerated),\n    EndTime = max(TimeGenerated),\n    totalDisabledAccountLoginAttempts = count(),\n    disabledAccountsTargettedCount = dcount(UserPrincipalName),\n    applicationsTargeted = dcount(AppDisplayName),\n    disabledAccountSet = make_set(UserPrincipalName, 100),\n    disabledApplicationSet = make_set(AppDisplayName, 100)\nby IPAddress, Type\n| order by totalDisabledAccountLoginAttempts desc) on IPAddress\n| project StartTime, EndTime, IPAddress, totalDisabledAccountLoginAttempts, disabledAccountsTargettedCount, disabledAccountSet, disabledApplicationSet, successfulApplicationSet, successfulAccountsTargettedCount, successfulAccountSigninSet, Type\n| order by totalDisabledAccountLoginAttempts};\nlet aadSignin = aadFunc(\"SigninLogs\");\nlet aadNonInt = aadFunc(\"AADNonInteractiveUserSignInLogs\");\nunion isfuzzy=true aadSignin, aadNonInt\n| join kind=leftouter (\n    BehaviorAnalytics\n    | where ActivityType in (\"FailedLogOn\", \"LogOn\")\n    | where EventSource =~ \"Azure AD\"\n    | project UsersInsights, DevicesInsights, ActivityInsights, InvestigationPriority, SourceIPAddress, UserPrincipalName\n    | project-rename IPAddress = SourceIPAddress\n    | summarize\n        Users = make_set(UserPrincipalName, 100),\n        UsersInsights = make_set(UsersInsights, 100),\n        DevicesInsights = make_set(DevicesInsights, 100),\n        IPInvestigationPriority = sum(InvestigationPriority)\n    by IPAddress\n) on IPAddress\n| extend SFRatio = toreal(toreal(disabledAccountsTargettedCount)/toreal(successfulAccountsTargettedCount))\n| where SFRatio >= 0.5\n| sort by IPInvestigationPriority desc\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess",
          "Persistence"
        ],
        "techniques": [
          "T1078",
          "T1098"
        ],
        "alertRuleTemplateName": "500c103a-0319-4d56-8e99-3cec8d860757",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPAddress"
              }
            ],
            "entityType": "IP"
          }
        ],
        "status": "Available",
        "templateVersion": "2.1.3",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Active Directory/Analytic Rules/SigninAttemptsByIPviaDisabledAccounts.yaml"
      }
    }
  ]
}