Missing Domain Controller Heartbeat

Severity: high
Time window: 2h
Group by: Computer
Author: Jose Sebastian Canos
Source: github.com/Azure/Azure-Sentinel

'This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.'

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1564` Hide Artifacts
Impact	`T1499` Endpoint Denial of Service

Rule body kusto

id: b8b8ba09-1e89-45a1-8bd7-691cd23bfa32
name: Missing Domain Controller Heartbeat
description: |
  'This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.'
severity: High
requiredDataConnectors: []
queryFrequency: 15m
queryPeriod: 2h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Impact
  - DefenseEvasion
relevantTechniques:
  - T1499
  - T1564
query: |
  let query_frequency = 15m;
  let missing_period = 1h;
  //Enter a reference list of hostnames for your DC servers
  let DCServersList = dynamic (["DC01.simulandlabs.com","DC02.simulandlabs.com"]);
  //Alternatively, a Watchlist can be used
  //let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;
  Heartbeat
  | summarize arg_max(TimeGenerated, *) by Computer
  | where Computer in (DCServersList)
  //You may specify the OS type of your Domain Controllers
  //| where OSType == 'Windows'
  | where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))
  | project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions
  | sort by TimeGenerated asc
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: Computer
version: 1.0.5
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Jose Sebastian Canos
    support:
        tier: Community
    providers: Microsoft
    categories:
        domains: [ "Security - Others" ]

Stages and Predicates

Parameters

let query_frequency = 15m;
let missing_period = 1h;
let DCServersList = dynamic (["DC01.simulandlabs.com","DC02.simulandlabs.com"]);

Stage 1: `source`

Heartbeat

Stage 2: `summarize`

| summarize arg_max(TimeGenerated, *) by Computer

Stage 3: `where`

| where Computer in (DCServersList)

Stage 4: `where`

| where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))

Stage 5: `project`

| project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions

Stage 6: `sort`

| sort by TimeGenerated asc

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
`Computer`	in	`DC01.simulandlabs.com` transforms: `cased` `DC02.simulandlabs.com` 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
`Computer`	`project`
`ComputerEnvironment`	`project`
`OSType`	`project`
`Solutions`	`project`
`TimeGenerated`	`project`
`Type`	`project`
`Version`	`project`

`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)

Missing Domain Controller Heartbeat

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `summarize`

Stage 3: `where`

Stage 4: `where`

Stage 5: `project`

Stage 6: `sort`

Indicators

Output fields

Keyboard shortcuts

Search operators

Missing Domain Controller Heartbeat

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: summarize

Stage 3: where

Stage 4: where

Stage 5: project

Stage 6: sort

Indicators

Output fields

Stage 1: `source`

Stage 2: `summarize`

Stage 3: `where`

Stage 4: `where`

Stage 5: `project`

Stage 6: `sort`