[Deprecated] Explicit MFA Deny

Status: available
Severity: medium
Time window: 1h
Source: github.com/Azure/Azure-Sentinel

'User explicitly denies MFA push, indicating that login was not expected and the account's password may be compromised. This rule is deprecated as of July-2024. Alternative rule with similar logic and contex from more data source is available at https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/MFARejectedbyUser.yaml'

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1110` Brute Force

Rule body kusto

id: a22740ec-fc1e-4c91-8de6-c29c6450ad00
name: '[Deprecated] Explicit MFA Deny'
description: |
  'User explicitly denies MFA push, indicating that login was not expected and the account's password may be compromised.
  This rule is deprecated as of July-2024. Alternative rule with similar logic and contex from more data source 
  is available at https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Entra%20ID/Analytic%20Rules/MFARejectedbyUser.yaml'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - SigninLogs
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AADNonInteractiveUserSignInLogs
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceInfo
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
query: |
  let aadFunc = (tableName: string) {
      table(tableName)
      | where ResultType == 500121
      | where Status has "MFA Denied; user declined the authentication" or Status has "MFA denied; Phone App Reported Fraud"
      | extend Type = Type, PublicIP = IPAddress
      | extend
          Name = tostring(split(UserPrincipalName, '@', 0)[0]),
          UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])
  };
  let aadSignin = aadFunc("SigninLogs");
  let dvcInfo = DeviceInfo
      | extend SensorHealthState = column_ifexists("SensorHealthState", "")
      | where OnboardingStatus == "Onboarded" and SensorHealthState == "Active"
      | project PublicIP, AadDeviceId;
  let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
  union isfuzzy=true aadSignin, aadNonInt
  | join kind=leftouter dvcInfo on PublicIP
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserPrincipalName
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: PublicIP
  - entityType: AzureResource
    fieldMappings:
      - identifier: ResourceId
        columnName: ResourceId
  - entityType: CloudApplication
    fieldMappings:
      - identifier: Name
        columnName: AppDisplayName
      - identifier: AppId
        columnName: AppId
version: 1.0.7
kind: Scheduled

Stages and Predicates

Parameters

let aadSignin = aadFunc("SigninLogs");
let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");

Let binding: `aadFunc`

let aadFunc = (tableName: string) {
    table(tableName)
    | where ResultType == 500121
    | where Status has "MFA Denied; user declined the authentication" or Status has "MFA denied; Phone App Reported Fraud"
    | extend Type = Type, PublicIP = IPAddress
    | extend
        Name = tostring(split(UserPrincipalName, '@', 0)[0]),
        UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])
};

Let binding: `dvcInfo`

let dvcInfo = DeviceInfo
    | extend SensorHealthState = column_ifexists("SensorHealthState", "")
    | where OnboardingStatus == "Onboarded" and SensorHealthState == "Active"
    | project PublicIP, AadDeviceId;

union `isfuzzy=true` (2 sources)

Each leg below queries one source; the rule matches if any leg does. Sources: aadSignin, aadNonInt

Leg 1: `aadSignin`

Leg 2: `aadNonInt`

Applied to the combined result

| join kind=leftouter dvcInfo on PublicIP

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
`OnboardingStatus`	eq	`Onboarded` transforms: `cased`
`SensorHealthState`	eq	`Active` transforms: `cased`

`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)

[Deprecated] Explicit MFA Deny

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `aadFunc`

Let binding: `dvcInfo`

union `isfuzzy=true` (2 sources)

Leg 1: `aadSignin`

Leg 2: `aadNonInt`

Applied to the combined result

Indicators

Keyboard shortcuts

Search operators

[Deprecated] Explicit MFA Deny

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: aadFunc

Let binding: dvcInfo

union isfuzzy=true (2 sources)

Leg 1: aadSignin

Leg 2: aadNonInt

Applied to the combined result

Indicators

Let binding: `aadFunc`

Let binding: `dvcInfo`

union `isfuzzy=true` (2 sources)

Leg 1: `aadSignin`

Leg 2: `aadNonInt`