Azure Policy Changed

Severity: low
Log types: Azure.Audit
Reference: https://learn.microsoft.com/en-us/entra/identity/authentication/overview-authentication
Source: github.com/panther-labs/panther-analysis

This detection looks for policy changes in AuditLogs

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1526` Cloud Service Discovery

Rule body yaml

AnalysisType: rule
Filename: azure_policy_changed.py
RuleID: "Azure.Audit.PolicyChanged"
DisplayName: "Azure Policy Changed"
Enabled: true
LogTypes:
  - Azure.Audit
Severity: Low
DedupPeriodMinutes: 10
Description: >
  This detection looks for policy changes in AuditLogs
Reports:
  MITRE ATT&CK:
    - TA0005:T1526
Runbook: >
  Verify if the change was authorized and review the modifications. If unauthorized, revert the policy, notify relevant teams, and investigate the user actions.

Reference: https://learn.microsoft.com/en-us/entra/identity/authentication/overview-authentication
SummaryAttributes:
  - properties:ServicePrincipalName
  - properties:UserPrincipalName
  - properties:initiatedBy:user:ipAddress
Tests:
  - Name: Policy Changed
    ExpectedResult: true
    Log:
        {
            "time": "2024-12-10T02:22:58.7270280Z",
            "resourceId": "/tenants/123145/providers/Microsoft.aadiam",
            "operationName": "Delete conditional access policy",
            "operationVersion": "1.0",
            "category": "AuditLogs",
            "tenantId": "12341234",
            "resultSignature": "None",
            "durationMs": 0,
            "callerIpAddress": "1.2.3.4",
            "correlationId": "1324515",
            "Level": "4",
            "properties": {
                "tenantId": "132455112",
                "resultType": "",
                "resultDescription": "",
                "operationName": "Delete conditional access policy",
                "identity": "",
                "tenantGeo": "NA",
                "id": "IPCGraph_af23466234",
                "category": "Policy",
                "correlationId": "23456234",
                "result": "success",
                "resultReason": null,
                "activityDisplayName": "Delete conditional access policy",
                "activityDateTime": "2024-11-27T02:22:58.727028+00:00",
                "loggedByService": "Conditional Access",
                "operationType": "Delete",
                "userAgent": null,
                "initiatedBy": {
                    "user": {
                        "id": "234526234",
                        "displayName": null,
                        "userPrincipalName": "aragorn@lotr.com",
                        "ipAddress": "1.2.3.4",
                        "roles": []
                    }
                },
                "targetResources": [
                    {
                        "id": "5e3cb481-2814-4295-b4cc-2440a6d66c86",
                        "displayName": "Outside MFA",
                        "type": "Policy",
                        "modifiedProperties": [
                            {
                                "displayName": "ConditionalAccessPolicy",
                                "oldValue": "{\"id\":\"5e3cb481-2814-4295-b4cc-2440a6d66c86\",\"displayName\":\"Outside MFA\",\"createdDateTime\":\"2024-11-27T02:22:19.8926587+00:00\",\"state\":\"enabled\",\"conditions\":{\"applications\":{\"includeApplications\":[\"None\"],\"excludeApplications\":[],\"includeUserActions\":[],\"includeAuthenticationContextClassReferences\":[],\"applicationFilter\":null},\"users\":{\"includeUsers\":[],\"excludeUsers\":[],\"includeGroups\":[],\"excludeGroups\":[],\"includeRoles\":[],\"excludeRoles\":[],\"includeGuestsOrExternalUsers\":{\"guestOrExternalUserTypes\":63,\"externalTenants\":{}}},\"userRiskLevels\":[],\"signInRiskLevels\":[],\"clientAppTypes\":[\"all\"],\"servicePrincipalRiskLevels\":[]},\"grantControls\":{\"operator\":\"OR\",\"builtInControls\":[\"mfa\"],\"customAuthenticationFactors\":[],\"termsOfUse\":[]}}",
                                "newValue": null
                            }
                        ],
                        "administrativeUnits": []
                    }
                ],
                "additionalDetails": [
                    {
                        "key": "Category",
                        "value": "Conditional Access"
                    }
                ]
            }
        }
  - Name: Policy Updated
    ExpectedResult: true
    Log:
        {
            "time": "2024-11-21T16:47:21.6424070Z",
            "resourceId": "/tenants/1234155/providers/Microsoft.aadiam",
            "operationName": "Update policy",
            "operationVersion": "1.0",
            "category": "AuditLogs",
            "tenantId": "12341235",
            "resultSignature": "None",
            "durationMs": 0,
            "callerIpAddress": "1.2.3.4",
            "correlationId": "124412123",
            "Level": "4",
            "properties": {
                "tenantId": "123515-5-1235",
                "resultType": "",
                "resultDescription": "",
                "operationName": "Update policy",
                "identity": "",
                "tenantGeo": "NA",
                "id": "Directory_12351123",
                "category": "Policy",
                "correlationId": "12341513",
                "result": "success",
                "resultReason": "",
                "activityDisplayName": "Delete policy",
                "activityDateTime": "2024-11-21T16:47:21.642407+00:00",
                "loggedByService": "Core Directory",
                "operationType": "Delete",
                "userAgent": null,
                "initiatedBy": {
                    "user": {
                        "id": "12345123",
                        "displayName": null,
                        "userPrincipalName": "denethor@lotr.com",
                        "ipAddress": "1.2.3.4",
                        "roles": []
                    }
                },
                "targetResources": [
                    {
                        "id": "123451516",
                        "displayName": "Require multifactor authentication for all users",
                        "type": "Policy",
                        "modifiedProperties": [],
                        "administrativeUnits": []
                    }
                ],
                "additionalDetails": [
                    {
                        "key": "User-Agent",
                        "value": "Microsoft Azure Graph Client Library 1.0"
                    }
                ]
            }
        }
  - Name: Policy Added
    ExpectedResult: false
    Log:
        {
            "time": "2024-11-21T16:47:21.6424070Z",
            "resourceId": "/tenants/1234155/providers/Microsoft.aadiam",
            "operationName": "Added policy",
            "operationVersion": "1.0",
            "category": "AuditLogs",
            "tenantId": "12341235",
            "resultSignature": "None",
            "durationMs": 0,
              "ipAddress": "1.2.3.4",
            "correlationId": "124412123",
            "Level": "4",
            "properties": {
                "tenantId": "123515-5-1235",
                "resultType": "",
                "resultDescription": "",
                "operationName": "Added policy",
                "identity": "",
                "tenantGeo": "NA",
                "id": "Directory_12351123",
                "category": "Policy",
                "correlationId": "12341513",
                "result": "success",
                "resultReason": "",
                "activityDisplayName": "Added policy",
                "activityDateTime": "2024-11-21T16:47:21.642407+00:00",
                "loggedByService": "Core Directory",
                "operationType": "Delete",
                "userAgent": null,
                "initiatedBy": {
                    "user": {
                        "id": "12345123",
                        "displayName": null,
                        "userPrincipalName": "Kratos@onmicrosoft.com",
                        "ipAddress": "1.2.3.4",
                        "roles": []
                    }
                },
                "targetResources": [
                    {
                        "id": "123451516",
                        "displayName": "Require multifactor authentication for all users",
                        "type": "Policy",
                        "modifiedProperties": [],
                        "administrativeUnits": []
                    }
                ],
                "additionalDetails": [
                    {
                        "key": "User-Agent",
                        "value": "Microsoft Azure Graph Client Library 1.0"
                    }
                ]
            }
        }

Detection logic

Condition

not (properties.result ne "success" or operationName not ends_with "policy")
not (operationName starts_with "Add" or operationName starts_with "Added")

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`operationName`	ends_with	`policy`
`properties.result`	ne	`success`
`operationName`	starts_with	`Add`
`operationName`	starts_with	`Added`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`operationName`	ends_with	`policy`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`operationName`
`category`	`properties.category`
`actor_id`	`properties.initiatedBy.user.id`
`actor_upn`	`properties.initiatedBy.user.userPrincipalName`
`source_ip_address`	`properties.initiatedBy.user.ipAddress`
`target_id`	`properties.targetResources.id`
`target_name`	`properties.targetResources.displayName`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)