Detection rules › Kusto

CYFIRMA - Brand Intelligence - Executive/People Impersonation Medium Rule

This is a third-party alert feed, not a detection over modeled telemetry. The vendor product raised the finding; this rule forwards it into the SIEM. It is searchable for reference but is excluded from the detection-rule browse and the ATT&CK coverage matrix.

Status: available
Severity: medium
Time window: 5m
Source: github.com/Azure/Azure-Sentinel

"This rule detects potential impersonation of executive or high-profile individuals across digital platforms such as social media. Such impersonation can be used to mislead stakeholders, perform social engineering attacks, or cause reputational damage to the organization. Timely detection is crucial to assess risk and take down malicious profiles to protect brand and executive identity."

MITRE ATT&CK coverage

Tactic	Techniques
Reconnaissance	`T1589.003` Gather Victim Identity Information: Employee Names
Resource Development	`T1585.001` Establish Accounts: Social Media Accounts
Initial Access	`T1566.002` Phishing: Spearphishing Link

Rule body kusto

id: 59aa22f2-5b4f-4679-b289-003228255413
name: CYFIRMA - Brand Intelligence - Executive/People Impersonation Medium Rule
description: |
  "This rule detects potential impersonation of executive or high-profile individuals across digital platforms such as social media. 
  Such impersonation can be used to mislead stakeholders, perform social engineering attacks, or cause reputational damage to the organization. 
  Timely detection is crucial to assess risk and take down malicious profiles to protect brand and executive identity."
version: 1.0.1
kind: Scheduled
severity: Medium
requiredDataConnectors:
  - connectorId: CyfirmaBrandIntelligenceAlertsDC
    dataTypes:
      - CyfirmaBIExecutivePeopleAlerts_CL
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: gt
triggerThreshold: 0
status: Available
tactics:
  - Reconnaissance
  - ResourceDevelopment
  - InitialAccess
relevantTechniques:
  - T1589.003
  - T1585.001
  - T1566.002
query: |
  // Medium severity - Executive/People Impersonation
  let timeFrame = 5m;
  CyfirmaBIExecutivePeopleAlerts_CL
  | where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())
  | extend
      Description=description,
      FirstSeen=first_seen,
      LastSeen=last_seen,
      RiskScore=risk_score,
      AlertUID=alert_uid,
      UID=uid,
      AssetType=asset_type,
      AssetValue=asset_value,
      Impact=impact,
      Recommendation=recommendation,
      PostedDate=posted_date,
      ProviderName='CYFIRMA',
      ProductName='DeCYFIR/DeTCT'
  | project
      TimeGenerated,
      Description,
      RiskScore,
      FirstSeen,
      LastSeen,
      AlertUID,
      UID,
      AssetType,
      AssetValue,
      Impact,
      Recommendation,
      PostedDate,
      ProductName,
      ProviderName
customDetails:
  AssetType: AssetType
  AssetValue: AssetValue
  Description: Description
  TimeGenerated: TimeGenerated
  FirstSeen: FirstSeen
  LastSeen: LastSeen
  AlertUID: AlertUID
  UID: UID
  Impact: Impact
  Recommendation: Recommendation
  PostedDate: PostedDate
  RiskScore: RiskScore
alertDetailsOverride:
  alertDisplayNameFormat: "CYFIRMA - Medium Severity Alert - Executive Impersonation - Suspicious Social Media Account Detected - {{AssetValue}} "
  alertDescriptionFormat: "{{Description}} "
  alertDynamicProperties:
    - alertProperty: ProductName
      value: ProductName
    - alertProperty: ProviderName
      value: ProviderName
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    enabled: false
    reopenClosedIncident: false
    lookbackDuration: PT5H
    matchingMethod: AllEntities
eventGroupingSettings:
  aggregationKind: AlertPerResult

Stages and Predicates

Parameters

let timeFrame = 5m;

Stage 1: `source`

CyfirmaBIExecutivePeopleAlerts_CL

Stage 2: `where`

| where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())

Stage 3: `extend`

| extend
    Description=description,
    FirstSeen=first_seen,
    LastSeen=last_seen,
    RiskScore=risk_score,
    AlertUID=alert_uid,
    UID=uid,
    AssetType=asset_type,
    AssetValue=asset_value,
    Impact=impact,
    Recommendation=recommendation,
    PostedDate=posted_date,
    ProviderName='CYFIRMA',
    ProductName='DeCYFIR/DeTCT'

Stage 4: `project`

| project
    TimeGenerated,
    Description,
    RiskScore,
    FirstSeen,
    LastSeen,
    AlertUID,
    UID,
    AssetType,
    AssetValue,
    Impact,
    Recommendation,
    PostedDate,
    ProductName,
    ProviderName

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
`severity`	eq	`High` 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
`AlertUID`	`project`
`AssetType`	`project`
`AssetValue`	`project`
`Description`	`project`
`FirstSeen`	`project`
`Impact`	`project`
`LastSeen`	`project`
`PostedDate`	`project`
`ProductName`	`project`
`ProviderName`	`project`
`Recommendation`	`project`
`RiskScore`	`project`
`TimeGenerated`	`project`
`UID`	`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)

CYFIRMA - Brand Intelligence - Executive/People Impersonation Medium Rule

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

CYFIRMA - Brand Intelligence - Executive/People Impersonation Medium Rule

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `project`