Detection rules › Kusto

CYFIRMA - Medium Severity Attack Surface based Vulnerabilities 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.

Severity: medium
Time window: 5m
Group by: name
Source: github.com/Azure/Azure-Sentinel

"This rule detects medium severity attack surface-based vulnerabilities from CYFIRMA's vulnerability intelligence data. It identifies vulnerabilities with a confidence score of 50 or higher, excluding those categorized as 'ASSET_VULNERABILITY', and generates alerts for assets that may be at risk."

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1133` External Remote Services, `T1190` Exploit Public-Facing Application
Execution	`T1059` Command and Scripting Interpreter, `T1203` Exploitation for Client Execution
Privilege Escalation	`T1068` Exploitation for Privilege Escalation, `T1548.002` Abuse Elevation Control Mechanism: Bypass User Account Control
Defense Impairment	`T1553` Subvert Trust Controls
Credential Access	`T1003` OS Credential Dumping
Lateral Movement	`T1021.002` Remote Services: SMB/Windows Admin Shares, `T1210` Exploitation of Remote Services

Rule body kusto

id: 4c1b282b-62f1-4783-bf40-94c44f0ae630
name: CYFIRMA - Medium Severity Attack Surface based Vulnerabilities Rule
description: |
  "This rule detects medium severity attack surface-based vulnerabilities from CYFIRMA's vulnerability intelligence data. It identifies vulnerabilities with a confidence score of 50 or higher, excluding those categorized as 'ASSET_VULNERABILITY', and generates alerts for assets that may be at risk."
version: 1.0.1
kind: Scheduled
severity: Medium
enabled: false
requiredDataConnectors:
  - connectorId: CyfirmaVulnerabilitiesIntelDC
    dataTypes:
      - CyfirmaVulnerabilities_CL
query: |
  // Medium severity - Attack Surface based Vulnerabilities
  let timeFrame= 5m;
  CyfirmaVulnerabilities_CL
  | extend parsed = parse_json(extensions)
  | extend extensionKeys = bag_keys(parsed)
  | mv-expand extensionKeys
  | extend extensionKeyStr = tostring(extensionKeys)
  | extend ext = parsed[extensionKeyStr]
  | extend props = ext.properties
  | extend 
      attack_complexity         = tostring(props.attack_complexity),
      cvss_score                = toreal(props.cvss_score),
      integrity_impact          = tostring(props.integrity_impact),
      impact_score              = tostring(props.impact_score),
      attack_vector             = tostring(props.attack_vector),
      privileges_required       = tostring(props.privileges_required),
      cvss_version              = tostring(props.cvss_version),
      user_interaction          = tostring(props.user_interaction),
      cvss_vector               = tostring(props.cvss_vector),
      scope                     = tostring(props.scope),
      confidentiality_impact    = tostring(props.confidentiality_impact),
      exploitability_score      = toreal(props.exploitability_score),
      products                  = tostring(props.products),
      technologies              = tostring(props.technologies),
      vendors                   = tostring(props.vendors),
      confidence_score          = toint(confidence),
      servers                   = tostring(props.servers),
      vulnerability_type        = tostring(props.vulnerability_type),
      vulnerability_category        = tostring(props.vulnerability_category),
      NetworkIPs                = tostring(props.ips),
      ProviderName              ='CYFIRMA',
      ProductName               ='DeCYFIR/DeTCT'
  | summarize arg_max(
                  integrity_impact,
                  TimeGenerated, 
                  id,
                  description,
                  confidence_score,
                  created,
                  modified,
                  attack_complexity,
                  cvss_score,
                  impact_score,
                  attack_vector,
                  privileges_required,
                  cvss_version,
                  user_interaction,
                  cvss_vector,
                  scope,
                  confidentiality_impact,
                  exploitability_score,
                  products,
                  technologies,
                  vendors,
                  ProviderName,
                  ProductName,
                  servers,
                  NetworkIPs,
                  vulnerability_type,
                  vulnerability_category
              )
      by name
  | where confidence_score >= 60 and vulnerability_category == 'ATTACK_SURFACE_VULNERABILITY' and TimeGenerated between (ago(timeFrame) .. now())
  | project 
      TimeGenerated,
      name,
      confidence_score,
      integrity_impact,
      attack_complexity,
      cvss_score,
      impact_score,
      attack_vector,
      UID = id,
      description,
      created,
      modified,
      privileges_required,
      cvss_version,
      user_interaction,
      cvss_vector,
      scope,
      confidentiality_impact,
      exploitability_score,
      products,
      technologies,
      vendors,
      ProviderName,
      ProductName,
      servers,
      NetworkIPs,
      vulnerability_type,
      vulnerability_category
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: GreaterThan
triggerThreshold: 0
suppressionDuration: 5m
suppressionEnabled: false
tactics:
  - Execution
  - LateralMovement
  - PrivilegeEscalation
  - InitialAccess
  - CredentialAccess
  - DefenseEvasion
relevantTechniques:
  - T1059
  - T1203
  - T1210
  - T1068
  - T1190
  - T1133
  - T1003
  - T1553
  - T1548.002
  - T1021.002
alertDetailsOverride:
  alertDisplayNameFormat: "CYFIRMA - Medium Severity Attack Surface based Vulnerability Identified - {{name}} "
  alertDescriptionFormat: "{{description}} "
  alertDynamicProperties:
    - alertProperty: ProductName
      value: ProductName
    - alertProperty: ProviderName
      value: ProviderName
customDetails:
  TimeGenerated: TimeGenerated
  CVE: name
  ConfidenceScore: confidence_score
  IntegrityImpact: integrity_impact
  AttackComplexity: attack_complexity
  CVSSScore: cvss_score
  ImpactScore: impact_score
  AttackVector: attack_vector
  ConfidentialImpact: confidentiality_impact
  PrivilegesRequired: privileges_required
  CVSSVersion: cvss_version
  UserInteraction: user_interaction
  CVSSVector: scope
  scope: exploitability_score
  ExploitabilityScore: modified
  Modified: products
  Products: technologies
  Vendors: vendors
  Technologies: technologies
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`

CyfirmaVulnerabilities_CL

Stage 2: `extend`

| extend parsed = parse_json(extensions)

Stage 3: `extend`

| extend extensionKeys = bag_keys(parsed)

Stage 4: `mv-expand`

| mv-expand extensionKeys

Stage 5: `extend` (4 consecutive steps)

| extend extensionKeyStr = tostring(extensionKeys)
| extend ext = parsed[extensionKeyStr]
| extend props = ext.properties
| extend 
    attack_complexity         = tostring(props.attack_complexity),
    cvss_score                = toreal(props.cvss_score),
    integrity_impact          = tostring(props.integrity_impact),
    impact_score              = tostring(props.impact_score),
    attack_vector             = tostring(props.attack_vector),
    privileges_required       = tostring(props.privileges_required),
    cvss_version              = tostring(props.cvss_version),
    user_interaction          = tostring(props.user_interaction),
    cvss_vector               = tostring(props.cvss_vector),
    scope                     = tostring(props.scope),
    confidentiality_impact    = tostring(props.confidentiality_impact),
    exploitability_score      = toreal(props.exploitability_score),
    products                  = tostring(props.products),
    technologies              = tostring(props.technologies),
    vendors                   = tostring(props.vendors),
    confidence_score          = toint(confidence),
    servers                   = tostring(props.servers),
    vulnerability_type        = tostring(props.vulnerability_type),
    vulnerability_category        = tostring(props.vulnerability_category),
    NetworkIPs                = tostring(props.ips),
    ProviderName              ='CYFIRMA',
    ProductName               ='DeCYFIR/DeTCT'

Stage 6: `summarize`

| summarize arg_max(
                integrity_impact,
                TimeGenerated, 
                id,
                description,
                confidence_score,
                created,
                modified,
                attack_complexity,
                cvss_score,
                impact_score,
                attack_vector,
                privileges_required,
                cvss_version,
                user_interaction,
                cvss_vector,
                scope,
                confidentiality_impact,
                exploitability_score,
                products,
                technologies,
                vendors,
                ProviderName,
                ProductName,
                servers,
                NetworkIPs,
                vulnerability_type,
                vulnerability_category
            )
    by name

Stage 7: `where`

| where confidence_score >= 60 and vulnerability_category == 'ATTACK_SURFACE_VULNERABILITY' and TimeGenerated between (ago(timeFrame) .. now())

Stage 8: `project`

| project 
    TimeGenerated,
    name,
    confidence_score,
    integrity_impact,
    attack_complexity,
    cvss_score,
    impact_score,
    attack_vector,
    UID = id,
    description,
    created,
    modified,
    privileges_required,
    cvss_version,
    user_interaction,
    cvss_vector,
    scope,
    confidentiality_impact,
    exploitability_score,
    products,
    technologies,
    vendors,
    ProviderName,
    ProductName,
    servers,
    NetworkIPs,
    vulnerability_type,
    vulnerability_category

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
`confidence_score`	ge	`60` transforms: `cased`
`vulnerability_category`	eq	`ATTACK_SURFACE_VULNERABILITY` 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
`NetworkIPs`	`project`
`ProductName`	`project`
`ProviderName`	`project`
`TimeGenerated`	`project`
`UID`	`project`
`attack_complexity`	`project`
`attack_vector`	`project`
`confidence_score`	`project`
`confidentiality_impact`	`project`
`created`	`project`
`cvss_score`	`project`
`cvss_vector`	`project`
`cvss_version`	`project`
`description`	`project`
`exploitability_score`	`project`
`impact_score`	`project`
`integrity_impact`	`project`
`modified`	`project`
`name`	`project`
`privileges_required`	`project`
`products`	`project`
`scope`	`project`
`servers`	`project`
`technologies`	`project`
`user_interaction`	`project`
`vendors`	`project`
`vulnerability_category`	`project`
`vulnerability_type`	`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 - Medium Severity Attack Surface based Vulnerabilities Rule

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `extend`

Stage 3: `extend`

Stage 4: `mv-expand`

Stage 5: `extend` (4 consecutive steps)

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

CYFIRMA - Medium Severity Attack Surface based Vulnerabilities Rule

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: extend

Stage 3: extend

Stage 4: mv-expand

Stage 5: extend (4 consecutive steps)

Stage 6: summarize

Stage 7: where

Stage 8: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `extend`

Stage 3: `extend`

Stage 4: `mv-expand`

Stage 5: `extend` (4 consecutive steps)

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `project`