Detection rules › Kusto

TI Map IP Entity to Azure SQL Security Audit Events

Severity
medium
Time window
14d
Group by
ClientIP, Id, ObservableValue, TI_ipEntity
Source
github.com/Azure/Azure-Sentinel

This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in SQL Security Audit Events.

MITRE ATT&CK coverage

TacticTechniques
Command & Control

Rules detecting the same action

These rules filter on the same operation.

Rule body

id: 239d987e-ee1b-4c49-b146-e88d682930a4
name: TI Map IP Entity to Azure SQL Security Audit Events
description: |
  This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in SQL Security Audit Events.
severity: Medium
requiredDataConnectors:
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelIndicators
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelIndicators
  - connectorId: AzureSql
    dataTypes:
      - AzureDiagnostics
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelIndicators
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h; // Look back 1 hour for AzureDiagnostics logs
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = ThreatIntelIndicators
  //extract key part of kv pair
       | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
       | where IndicatorType in ("ipv4-addr", "ipv6-addr", "network-traffic")
       | extend NetworkSourceIP = toupper(ObservableValue)
       | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
       | where TimeGenerated >= ago(ioc_lookBack)
       | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)
       | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
       | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
    | where IsActive and (ValidUntil > now() or isempty(ValidUntil));
  // Perform a join between IP indicators and AzureDiagnostics logs for SQL Security Audit events
  IP_Indicators
     | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
    // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
    | join kind=innerunique (
        AzureDiagnostics
        | where TimeGenerated >= ago(dt_lookBack)
        | where ResourceProvider == 'MICROSOFT.SQL'
        | where Category == 'SQLSecurityAuditEvents'
        | extend SQLSecurityAuditEvents_TimeGenerated = TimeGenerated
        | extend ClientIP = column_ifexists("client_ip_s", "Not Available")
        | extend Action = column_ifexists("action_name_s", "Not Available")
        | extend Application = column_ifexists("application_name_s", "Not Available")
        | extend HostName = column_ifexists("host_name_s", "Not Available")
    )
    on $left.TI_ipEntity == $right.ClientIP
    // Filter out logs that occurred after the expiration of the corresponding indicator
    | where SQLSecurityAuditEvents_TimeGenerated < ValidUntil
    // Group the results by IndicatorId and ClientIP, and keep the log entry with the latest timestamp
    | summarize SQLSecurityAuditEvents_TimeGenerated = arg_max(SQLSecurityAuditEvents_TimeGenerated, *) by Id, ClientIP
    // Select the desired output fields
    | extend Description = tostring(parse_json(Data).description)
    | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
    | project SQLSecurityAuditEvents_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
      TI_ipEntity, ResourceId, ClientIP, Action, Application, HostName,  NetworkSourceIP, Type
    // Rename the timestamp field
    | extend timestamp = SQLSecurityAuditEvents_TimeGenerated
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: ClientIP
version: 1.3.5
kind: Scheduled

Stages and Predicates

Stage 0: let

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_Indicators = ThreatIntelIndicators <inlined as stages below>;

Stage 1: source

ThreatIntelIndicators

Stage 2: extend

| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))

Stage 3: where

| where IndicatorType in ("ipv4-addr", "ipv6-addr", "network-traffic")

Stage 4: extend

| extend NetworkSourceIP = toupper(ObservableValue)

Stage 5: extend

| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)

Stage 6: where

| where TimeGenerated >= ago(ioc_lookBack)

Stage 7: extend

| extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)
TI_ipEntity =
ifisnotempty(NetworkSourceIP)NetworkSourceIP
elseNetworkSourceIP

Stage 8: extend

| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
TI_ipEntity =
ifisempty(TI_ipEntity) and isnotempty(NetworkSourceIP)NetworkSourceIP
elseTI_ipEntity

Stage 9: where

| where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."

Stage 10: summarize

| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue

Stage 11: where

| where IsActive and (ValidUntil > now() or isempty(ValidUntil))

Stage 12: project-reorder

| project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity

Stage 13: join

| join kind=innerunique (
      AzureDiagnostics
      | where TimeGenerated >= ago(dt_lookBack)
      | where ResourceProvider == 'MICROSOFT.SQL'
      | where Category == 'SQLSecurityAuditEvents'
      | extend SQLSecurityAuditEvents_TimeGenerated = TimeGenerated
      | extend ClientIP = column_ifexists("client_ip_s", "Not Available")
      | extend Action = column_ifexists("action_name_s", "Not Available")
      | extend Application = column_ifexists("application_name_s", "Not Available")
      | extend HostName = column_ifexists("host_name_s", "Not Available")
  )
  on $left.TI_ipEntity == $right.ClientIP

Stage 14: where

where SQLSecurityAuditEvents_TimeGenerated < ValidUntil

Stage 15: summarize

summarize SQLSecurityAuditEvents_TimeGenerated by Id, ClientIP

Stage 16: extend

extend Description

Stage 17: extend

extend ActivityGroupNames

Stage 18: project

project Action, ActivityGroupNames, Application, ClientIP, Confidence, Description, HostName, Id, NetworkSourceIP, ResourceId, SQLSecurityAuditEvents_TimeGenerated, TI_ipEntity, Type, ValidUntil

Stage 19: extend

extend timestamp

Indicators

These rows show field, operator, and value matches.

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
TI_ipEntitycidr_match10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16, 127.0.0.0/8excludes:TI_ipEntity
TI_ipEntitystarts_with127.excludes:TI_ipEntity field:"TI_ipEntity" value:"127."
TI_ipEntitystarts_with::excludes:TI_ipEntity field:"TI_ipEntity" value:"::"
TI_ipEntitystarts_withfe80excludes:TI_ipEntity field:"TI_ipEntity" value:"fe80"

Output fields

These fields are emitted when the rule matches.

FieldSource
Actionproject
ActivityGroupNamesproject
Applicationproject
ClientIPproject
Confidenceproject
Descriptionproject
HostNameproject
Idproject
NetworkSourceIPproject
ResourceIdproject
SQLSecurityAuditEvents_TimeGeneratedproject
TI_ipEntityproject
Typeproject
ValidUntilproject
timestampextend