Password spray attack against ADFSSignInLogs

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

'Identifies evidence of password spray activity against Connect Health for AD FS sign-in events by looking for failures from multiple accounts from the same IP address within a time window. Reference: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/ADFSSignInLogsPasswordSpray.md'

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1110` Brute Force

Rule body kusto

id: 5533fe80-905e-49d5-889a-df27d2c3976d
name: Password spray attack against ADFSSignInLogs
description: |
  'Identifies evidence of password spray activity against Connect Health for AD FS sign-in events by looking for failures from multiple accounts from the same IP address within a time window. Reference: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft%20Entra%20ID/ADFSSignInLogsPasswordSpray.md'
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - ADFSSignInLogs
severity: Medium
queryFrequency: 30m
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
query: |
  let queryfrequency = 30m;
  let accountthreshold = 10;
  let successCodes = dynamic([0, 50144]);
  ADFSSignInLogs
  | extend IngestionTime = ingestion_time()
  | where IngestionTime > ago(queryfrequency)
  | where not(todynamic(AuthenticationDetails)[0].authenticationMethod == "Integrated Windows Authentication")
  | summarize
      DistinctFailureCount = dcountif(UserPrincipalName, ResultType !in (successCodes)),
      DistinctSuccessCount = dcountif(UserPrincipalName, ResultType in (successCodes)),
      SuccessAccounts = make_set_if(UserPrincipalName, ResultType in (successCodes), 250),
      arg_min(TimeGenerated, *)
      by IPAddress
  | where DistinctFailureCount > DistinctSuccessCount and DistinctFailureCount >= accountthreshold
  //| extend SuccessAccounts = iff(array_length(SuccessAccounts) != 0, SuccessAccounts, dynamic(["null"]))
  //| mv-expand SuccessAccounts
  | project TimeGenerated, Category, OperationName, IPAddress, DistinctFailureCount, DistinctSuccessCount, SuccessAccounts, AuthenticationRequirement, ConditionalAccessStatus, IsInteractive, UserAgent, NetworkLocationDetails, DeviceDetail, TokenIssuerType, TokenIssuerName, ResourceIdentity
entityMappings:
- entityType: IP
  fieldMappings:
    - identifier: Address
      columnName: IPAddress
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

let queryfrequency = 30m;
let accountthreshold = 10;
let successCodes = dynamic([0, 50144]);

Stage 1: `source`

ADFSSignInLogs

Stage 2: `extend`

| extend IngestionTime = ingestion_time()

Stage 3: `where`

| where IngestionTime > ago(queryfrequency)

Stage 4: `where`

| where not(todynamic(AuthenticationDetails)[0].authenticationMethod == "Integrated Windows Authentication")

Stage 5: `summarize`

| summarize
    DistinctFailureCount = dcountif(UserPrincipalName, ResultType !in (successCodes)),
    DistinctSuccessCount = dcountif(UserPrincipalName, ResultType in (successCodes)),
    SuccessAccounts = make_set_if(UserPrincipalName, ResultType in (successCodes), 250),
    arg_min(TimeGenerated, *)
    by IPAddress

Threshold: gt DistinctSuccessCount

Stage 6: `where`

| where DistinctFailureCount > DistinctSuccessCount and DistinctFailureCount >= accountthreshold

Stage 7: `project`

| project TimeGenerated, Category, OperationName, IPAddress, DistinctFailureCount, DistinctSuccessCount, SuccessAccounts, AuthenticationRequirement, ConditionalAccessStatus, IsInteractive, UserAgent, NetworkLocationDetails, DeviceDetail, TokenIssuerType, TokenIssuerName, ResourceIdentity

Exclusions

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

Field	Kind	Excluded values
`authenticationMethod`	eq	`Integrated Windows Authentication`

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
`DistinctFailureCount`	ge	`10` transforms: `cased`
`DistinctFailureCount`	gt	`DistinctSuccessCount` transforms: `cased`

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
`AuthenticationRequirement`	`project`
`Category`	`project`
`ConditionalAccessStatus`	`project`
`DeviceDetail`	`project`
`DistinctFailureCount`	`project`
`DistinctSuccessCount`	`project`
`IPAddress`	`project`
`IsInteractive`	`project`
`NetworkLocationDetails`	`project`
`OperationName`	`project`
`ResourceIdentity`	`project`
`SuccessAccounts`	`project`
`TimeGenerated`	`project`
`TokenIssuerName`	`project`
`TokenIssuerType`	`project`
`UserAgent`	`project`

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`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)

Password spray attack against ADFSSignInLogs

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `extend`

Stage 3: `where`

Stage 4: `where`

Stage 5: `summarize`

Stage 6: `where`

Stage 7: `project`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Password spray attack against ADFSSignInLogs

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: extend

Stage 3: where

Stage 4: where

Stage 5: summarize

Stage 6: where

Stage 7: project

Exclusions

Indicators

Output fields

Stage 1: `source`

Stage 2: `extend`

Stage 3: `where`

Stage 4: `where`

Stage 5: `summarize`

Stage 6: `where`

Stage 7: `project`