GSA Enriched Office 365 - Office Policy Tampering

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Id	0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb
Rulename	GSA Enriched Office 365 - Office Policy Tampering
Description	Identifies if any tampering is done to either audit log, ATP Safelink, SafeAttachment, AntiPhish, or Dlp policy. An adversary may use this technique to evade detection or avoid other policy-based defenses. References: https://docs.microsoft.com/powershell/module/exchange/advanced-threat-protection/remove-antiphishrule?view=exchange-ps.
Severity	Medium
Tactics	Persistence DefenseEvasion
Techniques	T1098 T1562
Required data connectors	AzureActiveDirectory Office365
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/Global Secure Access/Analytic Rules/Office 365 - office_policytampering.yaml
Version	2.0.6
Arm template	0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb.json

KQL

// Query for EnrichedMicrosoft365AuditLogs
let enrichedOpList = EnrichedMicrosoft365AuditLogs 
    | summarize by Operation
    | where Operation has_any ("Remove", "Disable")
    | where Operation contains "AntiPhish" 
        or Operation contains "SafeAttachment" 
        or Operation contains "SafeLinks" 
        or Operation contains "Dlp" 
        or Operation contains "Audit"
    | summarize make_set(Operation, 500);

let enrichedLogs = EnrichedMicrosoft365AuditLogs
    | where RecordType == "ExchangeAdmin"
    | where UserType in~ ("Admin", "DcAdmin")
    | where Operation in~ (enrichedOpList)
    | extend ClientIPOnly = case( 
        ClientIp has ".", tostring(split(ClientIp, ":")[0]), 
        ClientIp has "[", tostring(trim_start(@'[[]', tostring(split(ClientIp, "]")[0]))),
        ClientIp
      )  
    | extend Port = case(
        ClientIp has ".", tostring(split(ClientIp, ":")[1]),
        ClientIp has "[", tostring(split(ClientIp, "]:")[1]),
        ""
      )
    | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() 
        by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters = tostring(AdditionalProperties.Parameters)
    | extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1]);

// Query for OfficeActivity
let officeOpList = OfficeActivity 
    | summarize by Operation
    | where Operation has_any ("Remove", "Disable")
    | where Operation contains "AntiPhish" 
        or Operation contains "SafeAttachment" 
        or Operation contains "SafeLinks" 
        or Operation contains "Dlp" 
        or Operation contains "Audit"
    | summarize make_set(Operation, 500);

let officeLogs = OfficeActivity
    | where RecordType =~ "ExchangeAdmin"
    | where UserType in~ ("Admin","DcAdmin")
    | where Operation in~ (officeOpList)
    | extend ClientIPOnly = case( 
        ClientIP has ".", tostring(split(ClientIP,":")[0]), 
        ClientIP has "[", tostring(trim_start(@'[[]', tostring(split(ClientIP,"]")[0]))),
        ClientIP
      )  
    | extend Port = case(
        ClientIP has ".", tostring(split(ClientIP,":")[1]),
        ClientIP has "[", tostring(split(ClientIP, "]:")[1]),
        ""
      )
    | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() 
        by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters
    | extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1]);

// Combine Enriched Logs and Office Activity Logs
union isfuzzy=true enrichedLogs, officeLogs
| summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), TotalOperationCount = sum(OperationCount) 
    by Operation, UserType, UserId, ClientIP, Port, ResultStatus, Parameters, AccountName, AccountUPNSuffix
| order by StartTimeUtc desc;

YAML

query: |
  // Query for EnrichedMicrosoft365AuditLogs
  let enrichedOpList = EnrichedMicrosoft365AuditLogs 
      | summarize by Operation
      | where Operation has_any ("Remove", "Disable")
      | where Operation contains "AntiPhish" 
          or Operation contains "SafeAttachment" 
          or Operation contains "SafeLinks" 
          or Operation contains "Dlp" 
          or Operation contains "Audit"
      | summarize make_set(Operation, 500);

  let enrichedLogs = EnrichedMicrosoft365AuditLogs
      | where RecordType == "ExchangeAdmin"
      | where UserType in~ ("Admin", "DcAdmin")
      | where Operation in~ (enrichedOpList)
      | extend ClientIPOnly = case( 
          ClientIp has ".", tostring(split(ClientIp, ":")[0]), 
          ClientIp has "[", tostring(trim_start(@'[[]', tostring(split(ClientIp, "]")[0]))),
          ClientIp
        )  
      | extend Port = case(
          ClientIp has ".", tostring(split(ClientIp, ":")[1]),
          ClientIp has "[", tostring(split(ClientIp, "]:")[1]),
          ""
        )
      | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() 
          by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters = tostring(AdditionalProperties.Parameters)
      | extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1]);

  // Query for OfficeActivity
  let officeOpList = OfficeActivity 
      | summarize by Operation
      | where Operation has_any ("Remove", "Disable")
      | where Operation contains "AntiPhish" 
          or Operation contains "SafeAttachment" 
          or Operation contains "SafeLinks" 
          or Operation contains "Dlp" 
          or Operation contains "Audit"
      | summarize make_set(Operation, 500);

  let officeLogs = OfficeActivity
      | where RecordType =~ "ExchangeAdmin"
      | where UserType in~ ("Admin","DcAdmin")
      | where Operation in~ (officeOpList)
      | extend ClientIPOnly = case( 
          ClientIP has ".", tostring(split(ClientIP,":")[0]), 
          ClientIP has "[", tostring(trim_start(@'[[]', tostring(split(ClientIP,"]")[0]))),
          ClientIP
        )  
      | extend Port = case(
          ClientIP has ".", tostring(split(ClientIP,":")[1]),
          ClientIP has "[", tostring(split(ClientIP, "]:")[1]),
          ""
        )
      | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() 
          by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters
      | extend AccountName = tostring(split(UserId, "@")[0]), AccountUPNSuffix = tostring(split(UserId, "@")[1]);

  // Combine Enriched Logs and Office Activity Logs
  union isfuzzy=true enrichedLogs, officeLogs
  | summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), TotalOperationCount = sum(OperationCount) 
      by Operation, UserType, UserId, ClientIP, Port, ResultStatus, Parameters, AccountName, AccountUPNSuffix
  | order by StartTimeUtc desc;  
relevantTechniques:
- T1098
- T1562
name: GSA Enriched Office 365 - Office Policy Tampering
severity: Medium
triggerThreshold: 0
description: |
  Identifies if any tampering is done to either audit log, ATP Safelink, SafeAttachment, AntiPhish, or Dlp policy. 
  An adversary may use this technique to evade detection or avoid other policy-based defenses.
  References: https://docs.microsoft.com/powershell/module/exchange/advanced-threat-protection/remove-antiphishrule?view=exchange-ps.  
status: Available
triggerOperator: gt
tactics:
- Persistence
- DefenseEvasion
entityMappings:
- fieldMappings:
  - columnName: UserId
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: ClientIP
    identifier: Address
  entityType: IP
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - EnrichedMicrosoft365AuditLogs
- connectorId: Office365
  dataTypes:
  - OfficeActivity (Exchange)
id: 0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/Office 365 - office_policytampering.yaml
queryPeriod: 1d
queryFrequency: 1d
version: 2.0.6
kind: Scheduled

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb')]",
      "properties": {
        "alertRuleTemplateName": "0f1f2b17-f9d6-4d2a-a0fb-a7ae1659e3eb",
        "customDetails": null,
        "description": "Identifies if any tampering is done to either audit log, ATP Safelink, SafeAttachment, AntiPhish, or Dlp policy. \nAn adversary may use this technique to evade detection or avoid other policy-based defenses.\nReferences: https://docs.microsoft.com/powershell/module/exchange/advanced-threat-protection/remove-antiphishrule?view=exchange-ps.\n",
        "displayName": "GSA Enriched Office 365 - Office Policy Tampering",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UserId",
                "identifier": "FullName"
              },
              {
                "columnName": "AccountName",
                "identifier": "Name"
              },
              {
                "columnName": "AccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "ClientIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/Office 365 - office_policytampering.yaml",
        "query": "// Query for EnrichedMicrosoft365AuditLogs\nlet enrichedOpList = EnrichedMicrosoft365AuditLogs \n    | summarize by Operation\n    | where Operation has_any (\"Remove\", \"Disable\")\n    | where Operation contains \"AntiPhish\" \n        or Operation contains \"SafeAttachment\" \n        or Operation contains \"SafeLinks\" \n        or Operation contains \"Dlp\" \n        or Operation contains \"Audit\"\n    | summarize make_set(Operation, 500);\n\nlet enrichedLogs = EnrichedMicrosoft365AuditLogs\n    | where RecordType == \"ExchangeAdmin\"\n    | where UserType in~ (\"Admin\", \"DcAdmin\")\n    | where Operation in~ (enrichedOpList)\n    | extend ClientIPOnly = case( \n        ClientIp has \".\", tostring(split(ClientIp, \":\")[0]), \n        ClientIp has \"[\", tostring(trim_start(@'[[]', tostring(split(ClientIp, \"]\")[0]))),\n        ClientIp\n      )  \n    | extend Port = case(\n        ClientIp has \".\", tostring(split(ClientIp, \":\")[1]),\n        ClientIp has \"[\", tostring(split(ClientIp, \"]:\")[1]),\n        \"\"\n      )\n    | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() \n        by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters = tostring(AdditionalProperties.Parameters)\n    | extend AccountName = tostring(split(UserId, \"@\")[0]), AccountUPNSuffix = tostring(split(UserId, \"@\")[1]);\n\n// Query for OfficeActivity\nlet officeOpList = OfficeActivity \n    | summarize by Operation\n    | where Operation has_any (\"Remove\", \"Disable\")\n    | where Operation contains \"AntiPhish\" \n        or Operation contains \"SafeAttachment\" \n        or Operation contains \"SafeLinks\" \n        or Operation contains \"Dlp\" \n        or Operation contains \"Audit\"\n    | summarize make_set(Operation, 500);\n\nlet officeLogs = OfficeActivity\n    | where RecordType =~ \"ExchangeAdmin\"\n    | where UserType in~ (\"Admin\",\"DcAdmin\")\n    | where Operation in~ (officeOpList)\n    | extend ClientIPOnly = case( \n        ClientIP has \".\", tostring(split(ClientIP,\":\")[0]), \n        ClientIP has \"[\", tostring(trim_start(@'[[]', tostring(split(ClientIP,\"]\")[0]))),\n        ClientIP\n      )  \n    | extend Port = case(\n        ClientIP has \".\", tostring(split(ClientIP,\":\")[1]),\n        ClientIP has \"[\", tostring(split(ClientIP, \"]:\")[1]),\n        \"\"\n      )\n    | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), OperationCount = count() \n        by Operation, UserType, UserId, ClientIP = ClientIPOnly, Port, ResultStatus, Parameters\n    | extend AccountName = tostring(split(UserId, \"@\")[0]), AccountUPNSuffix = tostring(split(UserId, \"@\")[1]);\n\n// Combine Enriched Logs and Office Activity Logs\nunion isfuzzy=true enrichedLogs, officeLogs\n| summarize StartTimeUtc = min(StartTimeUtc), EndTimeUtc = max(EndTimeUtc), TotalOperationCount = sum(OperationCount) \n    by Operation, UserType, UserId, ClientIP, Port, ResultStatus, Parameters, AccountName, AccountUPNSuffix\n| order by StartTimeUtc desc;\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "Persistence"
        ],
        "techniques": [
          "T1098",
          "T1562"
        ],
        "templateVersion": "2.0.6",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}