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Possible AiTM Phishing Attempt Against Microsoft Entra ID

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Id16daa67c-b137-48dc-8eb7-76598a44791a
RulenamePossible AiTM Phishing Attempt Against Microsoft Entra ID
DescriptionThreat actors may attempt to phish users in order to hijack a users sign-in session, and skip the authentication process even if the user had enabled multifactor authentication (MFA) by stealing and replaying stolen credentials and session cookies.

This detection looks for successful Microsoft Entra ID sign ins that had a high risk profile, indicating it had suspicious characteristics such as an unusual location, ISP, user agent, or use of anonymizer services.

It then looks for a network connection to the IP address that made the sign in immediately before the sign in, that may indicate a user connecting to a phishing site at that IP address and having their authentication session hijacked.

Ref: https://www.microsoft.com/security/blog/2022/07/12/from-cookie-theft-to-bec-attackers-use-aitm-phishing-sites-as-entry-point-to-further-financial-fraud/
SeverityMedium
TacticsInitialAccess
DefenseEvasion
CredentialAccess
TechniquesT1078.004
T1557
T1111
Required data connectorsAzureActiveDirectory
Zscaler
KindScheduled
Query frequency1h
Query period1d
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SecurityThreatEssentialSolution/Analytic Rules/PossibleAiTMPhishingAttemptAgainstAAD.yaml
Version1.0.4
Arm template16daa67c-b137-48dc-8eb7-76598a44791a.json
Deploy To Azure
let time_threshold = 10m;
let RiskySignins = materialize (SigninLogs
| where TimeGenerated > ago(1d)
| where ResultType == 0
| where RiskLevelDuringSignIn =~ "high" or RiskLevelAggregated =~ "high"
| extend SignInTime = TimeGenerated, Name=split(UserPrincipalName, "@")[0], UPNSuffix=split(UserPrincipalName, "@")[1]);
let ips = todynamic(toscalar(RiskySignins | summarize make_list(IPAddress)));
RiskySignins
| join kind=inner (_Im_WebSession(starttime=ago(1d), ipaddr_has_any_prefix=ips, eventresult="Success", pack=True))
on $left.IPAddress == $right.DstIpAddr
| where EventStartTime < TimeGenerated
| extend TimeDelta = TimeGenerated - EventStartTime
| where TimeDelta <= time_threshold
| extend NetworkEventStartTime = EventStartTime, NetworkEventEndTime = EventEndTime
| extend SrcUsername = column_ifexists("SrcUsername", "Unknown")
| project-reorder SignInTime, UserPrincipalName, IPAddress, AppDisplayName, ClientAppUsed, DeviceDetail, LocationDetails, NetworkLocationDetails, RiskEventTypes, UserAgent, NetworkEventStartTime, NetworkEventEndTime, SrcIpAddr, DstIpAddr, DstPortNumber, Dvc, DvcHostname, SrcBytes, NetworkProtocol, SrcUsername
alertDetailsOverride:
  alertDisplayNameFormat: Possible AiTM Phishing Attempt Against {{UserPrincipalName}} From {{IPAddress}}
  alertDescriptionFormat: |
    Threat actors may attempt to phish users in order to hijack a users sign-in session, and skip the authentication process even if the user had enabled multifactor authentication (MFA) by stealing and replaying stolen credentials and session cookies.
    This detection looks for successful Microsoft Entra ID sign ins (in this case from {{UserPrincipalName}}) that had a high risk profile, indicating it had suspicious characteristics such as an unusual location, ISP, user agent, or use of anonymizer services.
    It then looks for a network connection to the IP address (in this case {{IPAddress}}) that made the sign in immediately before the sign in, that may indicate a user connecting to a phishing site at that IP address and having their authentication session hijacked.
    Ref: https://www.microsoft.com/security/blog/2022/07/12/from-cookie-theft-to-bec-attackers-use-aitm-phishing-sites-as-entry-point-to-further-financial-fraud/    
queryFrequency: 1h
tactics:
- InitialAccess
- DefenseEvasion
- CredentialAccess
queryPeriod: 1d
kind: Scheduled
relevantTechniques:
- T1078.004
- T1557
- T1111
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SecurityThreatEssentialSolution/Analytic Rules/PossibleAiTMPhishingAttemptAgainstAAD.yaml
description: |
  'Threat actors may attempt to phish users in order to hijack a users sign-in session, and skip the authentication process even if the user had enabled multifactor authentication (MFA) by stealing and replaying stolen credentials and session cookies.
  This detection looks for successful Microsoft Entra ID sign ins that had a high risk profile, indicating it had suspicious characteristics such as an unusual location, ISP, user agent, or use of anonymizer services.
  It then looks for a network connection to the IP address that made the sign in immediately before the sign in, that may indicate a user connecting to a phishing site at that IP address and having their authentication session hijacked.
  Ref: https://www.microsoft.com/security/blog/2022/07/12/from-cookie-theft-to-bec-attackers-use-aitm-phishing-sites-as-entry-point-to-further-financial-fraud/'  
requiredDataConnectors:
- dataTypes:
  - SigninLogs
  connectorId: AzureActiveDirectory
- dataTypes:
  - CommonSecurityLog (Zscaler)
  connectorId: Zscaler
version: 1.0.4
triggerThreshold: 0
severity: Medium
triggerOperator: gt
id: 16daa67c-b137-48dc-8eb7-76598a44791a
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: Name
    identifier: Name
  - columnName: UPNSuffix
    identifier: UPNSuffix
- entityType: IP
  fieldMappings:
  - columnName: IPAddress
    identifier: Address
status: Available
name: Possible AiTM Phishing Attempt Against Microsoft Entra ID
query: |
  let time_threshold = 10m;
  let RiskySignins = materialize (SigninLogs
  | where TimeGenerated > ago(1d)
  | where ResultType == 0
  | where RiskLevelDuringSignIn =~ "high" or RiskLevelAggregated =~ "high"
  | extend SignInTime = TimeGenerated, Name=split(UserPrincipalName, "@")[0], UPNSuffix=split(UserPrincipalName, "@")[1]);
  let ips = todynamic(toscalar(RiskySignins | summarize make_list(IPAddress)));
  RiskySignins
  | join kind=inner (_Im_WebSession(starttime=ago(1d), ipaddr_has_any_prefix=ips, eventresult="Success", pack=True))
  on $left.IPAddress == $right.DstIpAddr
  | where EventStartTime < TimeGenerated
  | extend TimeDelta = TimeGenerated - EventStartTime
  | where TimeDelta <= time_threshold
  | extend NetworkEventStartTime = EventStartTime, NetworkEventEndTime = EventEndTime
  | extend SrcUsername = column_ifexists("SrcUsername", "Unknown")
  | project-reorder SignInTime, UserPrincipalName, IPAddress, AppDisplayName, ClientAppUsed, DeviceDetail, LocationDetails, NetworkLocationDetails, RiskEventTypes, UserAgent, NetworkEventStartTime, NetworkEventEndTime, SrcIpAddr, DstIpAddr, DstPortNumber, Dvc, DvcHostname, SrcBytes, NetworkProtocol, SrcUsername  
{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/16daa67c-b137-48dc-8eb7-76598a44791a')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/16daa67c-b137-48dc-8eb7-76598a44791a')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "Threat actors may attempt to phish users in order to hijack a users sign-in session, and skip the authentication process even if the user had enabled multifactor authentication (MFA) by stealing and replaying stolen credentials and session cookies.\nThis detection looks for successful Microsoft Entra ID sign ins (in this case from {{UserPrincipalName}}) that had a high risk profile, indicating it had suspicious characteristics such as an unusual location, ISP, user agent, or use of anonymizer services.\nIt then looks for a network connection to the IP address (in this case {{IPAddress}}) that made the sign in immediately before the sign in, that may indicate a user connecting to a phishing site at that IP address and having their authentication session hijacked.\nRef: https://www.microsoft.com/security/blog/2022/07/12/from-cookie-theft-to-bec-attackers-use-aitm-phishing-sites-as-entry-point-to-further-financial-fraud/\n",
          "alertDisplayNameFormat": "Possible AiTM Phishing Attempt Against {{UserPrincipalName}} From {{IPAddress}}"
        },
        "alertRuleTemplateName": "16daa67c-b137-48dc-8eb7-76598a44791a",
        "customDetails": null,
        "description": "'Threat actors may attempt to phish users in order to hijack a users sign-in session, and skip the authentication process even if the user had enabled multifactor authentication (MFA) by stealing and replaying stolen credentials and session cookies.\nThis detection looks for successful Microsoft Entra ID sign ins that had a high risk profile, indicating it had suspicious characteristics such as an unusual location, ISP, user agent, or use of anonymizer services.\nIt then looks for a network connection to the IP address that made the sign in immediately before the sign in, that may indicate a user connecting to a phishing site at that IP address and having their authentication session hijacked.\nRef: https://www.microsoft.com/security/blog/2022/07/12/from-cookie-theft-to-bec-attackers-use-aitm-phishing-sites-as-entry-point-to-further-financial-fraud/'\n",
        "displayName": "Possible AiTM Phishing Attempt Against Microsoft Entra ID",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SecurityThreatEssentialSolution/Analytic Rules/PossibleAiTMPhishingAttemptAgainstAAD.yaml",
        "query": "let time_threshold = 10m;\nlet RiskySignins = materialize (SigninLogs\n| where TimeGenerated > ago(1d)\n| where ResultType == 0\n| where RiskLevelDuringSignIn =~ \"high\" or RiskLevelAggregated =~ \"high\"\n| extend SignInTime = TimeGenerated, Name=split(UserPrincipalName, \"@\")[0], UPNSuffix=split(UserPrincipalName, \"@\")[1]);\nlet ips = todynamic(toscalar(RiskySignins | summarize make_list(IPAddress)));\nRiskySignins\n| join kind=inner (_Im_WebSession(starttime=ago(1d), ipaddr_has_any_prefix=ips, eventresult=\"Success\", pack=True))\non $left.IPAddress == $right.DstIpAddr\n| where EventStartTime < TimeGenerated\n| extend TimeDelta = TimeGenerated - EventStartTime\n| where TimeDelta <= time_threshold\n| extend NetworkEventStartTime = EventStartTime, NetworkEventEndTime = EventEndTime\n| extend SrcUsername = column_ifexists(\"SrcUsername\", \"Unknown\")\n| project-reorder SignInTime, UserPrincipalName, IPAddress, AppDisplayName, ClientAppUsed, DeviceDetail, LocationDetails, NetworkLocationDetails, RiskEventTypes, UserAgent, NetworkEventStartTime, NetworkEventEndTime, SrcIpAddr, DstIpAddr, DstPortNumber, Dvc, DvcHostname, SrcBytes, NetworkProtocol, SrcUsername\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess",
          "DefenseEvasion",
          "InitialAccess"
        ],
        "techniques": [
          "T1078",
          "T1111",
          "T1557"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}