Distributed Password cracking attempts in Microsoft Entra ID

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

'Identifies distributed password cracking attempts from the Microsoft Entra ID SigninLogs. The query looks for unusually high number of failed password attempts coming from multiple locations for a user account. References: https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes 50053 Account is locked because the user tried to sign in too many times with an incorrect user ID or password. 50055 Invalid password, entered expired password. 50056 Invalid or null password - Password does not exist in store for this user. 50126 Invalid username or password, or invalid on-premises username or password.'

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1110` Brute Force

Rule body kusto

id: bfb1c90f-8006-4325-98be-c7fffbc254d6
name: Distributed Password cracking attempts in Microsoft Entra ID
description: |
  'Identifies distributed password cracking attempts from the Microsoft Entra ID SigninLogs.
  The query looks for unusually high number of failed password attempts coming from multiple locations for a user account.
  References: https://docs.microsoft.com/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes
  50053   Account is locked because the user tried to sign in too many times with an incorrect user ID or password.
  50055   Invalid password, entered expired password.
  50056   Invalid or null password - Password does not exist in store for this user.
  50126   Invalid username or password, or invalid on-premises username or password.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - SigninLogs
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AADNonInteractiveUserSignInLogs
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
query: |
  let s_threshold = 30;
  let l_threshold = 3;
  let aadFunc = (tableName:string){
  table(tableName)
  | where OperationName =~ "Sign-in activity"
  // Error codes that we want to look at as they are related to the use of incorrect password.
  | where ResultType in ("50126", "50053" , "50055", "50056")
  | extend DeviceDetail = todynamic(DeviceDetail), Status = todynamic(DeviceDetail), LocationDetails = todynamic(LocationDetails)
  | extend OS = DeviceDetail.operatingSystem, Browser = DeviceDetail.browser
  | extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails)
  | extend LocationString = strcat(tostring(LocationDetails.countryOrRegion), "/", tostring(LocationDetails.state), "/", tostring(LocationDetails.city))
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), LocationCount=dcount(LocationString), Location = make_set(LocationString,100),
  IPAddress = make_set(IPAddress,100), IPAddressCount = dcount(IPAddress), AppDisplayName = make_set(AppDisplayName,100), ResultDescription = make_set(ResultDescription,50),
  Browser = make_set(Browser,20), OS = make_set(OS,20), SigninCount = count() by UserPrincipalName, Type
  // Setting a generic threshold - Can be different for different environment
  | where SigninCount > s_threshold and LocationCount >= l_threshold
  | extend Location = tostring(Location), IPAddress = tostring(IPAddress), AppDisplayName = tostring(AppDisplayName), ResultDescription = tostring(ResultDescription), Browser = tostring(Browser), OS = tostring(OS)
  | extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])};
  let aadSignin = aadFunc("SigninLogs");
  let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");
  union isfuzzy=true aadSignin, aadNonInt
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserPrincipalName
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
version: 1.0.5
kind: Scheduled

Stages and Predicates

Parameters

let s_threshold = 30;
let l_threshold = 3;
let aadSignin = aadFunc("SigninLogs");
let aadNonInt = aadFunc("AADNonInteractiveUserSignInLogs");

Let binding: `aadFunc`

let aadFunc = (tableName:string){
table(tableName)
| where OperationName =~ "Sign-in activity"
| where ResultType in ("50126", "50053" , "50055", "50056")
| extend DeviceDetail = todynamic(DeviceDetail), Status = todynamic(DeviceDetail), LocationDetails = todynamic(LocationDetails)
| extend OS = DeviceDetail.operatingSystem, Browser = DeviceDetail.browser
| extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails)
| extend LocationString = strcat(tostring(LocationDetails.countryOrRegion), "/", tostring(LocationDetails.state), "/", tostring(LocationDetails.city))
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), LocationCount=dcount(LocationString), Location = make_set(LocationString,100),
IPAddress = make_set(IPAddress,100), IPAddressCount = dcount(IPAddress), AppDisplayName = make_set(AppDisplayName,100), ResultDescription = make_set(ResultDescription,50),
Browser = make_set(Browser,20), OS = make_set(OS,20), SigninCount = count() by UserPrincipalName, Type
| where SigninCount > s_threshold and LocationCount >= l_threshold
| extend Location = tostring(Location), IPAddress = tostring(IPAddress), AppDisplayName = tostring(AppDisplayName), ResultDescription = tostring(ResultDescription), Browser = tostring(Browser), OS = tostring(OS)
| extend Name = tostring(split(UserPrincipalName,'@',0)[0]), UPNSuffix = tostring(split(UserPrincipalName,'@',1)[0])};

Derived from s_threshold, l_threshold.

union `isfuzzy=true` (2 sources)

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

`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)

Distributed Password cracking attempts in Microsoft Entra ID

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `aadFunc`

union `isfuzzy=true` (2 sources)

Leg 1: `aadSignin`

Leg 2: `aadNonInt`

Keyboard shortcuts

Search operators

Distributed Password cracking attempts in Microsoft Entra ID

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: aadFunc

union isfuzzy=true (2 sources)

Leg 1: aadSignin

Leg 2: aadNonInt

Let binding: `aadFunc`

union `isfuzzy=true` (2 sources)

Leg 1: `aadSignin`

Leg 2: `aadNonInt`