Detection rules › Kusto

TI Map IP Entity to Azure SQL Security Audit Events

Severity
medium
Time window
14d
Group by
ClientIP, IndicatorId, 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: d0aa8969-1bbe-4da3-9e76-09e5f67c9d85
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:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: AzureSql
    dataTypes:
      - AzureDiagnostics
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
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 = ThreatIntelligenceIndicator
    | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
    | where TimeGenerated >= ago(ioc_lookBack)
    | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
    | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
    | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, 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 IndicatorId
    | where Active == true and ExpirationDateTime > now();
  // Perform a join between IP indicators and AzureDiagnostics logs for SQL Security Audit events
  IP_Indicators
    // 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 < ExpirationDateTime
    // Group the results by IndicatorId and ClientIP, and keep the log entry with the latest timestamp
    | summarize SQLSecurityAuditEvents_TimeGenerated = arg_max(SQLSecurityAuditEvents_TimeGenerated, *) by IndicatorId, ClientIP
    // Select the desired output fields
    | project SQLSecurityAuditEvents_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
      TI_ipEntity, ResourceId, ClientIP, Action, Application, HostName, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
    // Rename the timestamp field
    | extend timestamp = SQLSecurityAuditEvents_TimeGenerated
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: ClientIP
version: 1.3.2
kind: Scheduled

Stages and Predicates

Stage 0: let

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

Stage 1: source

ThreatIntelligenceIndicator

Stage 2: where

| where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)

Stage 3: where

| where TimeGenerated >= ago(ioc_lookBack)

Stage 4: extend (3 consecutive steps)

| extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
TI_ipEntity =
ifisnotempty(NetworkIP)NetworkIP
elseNetworkDestinationIP

Stage 5: where

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

Stage 6: summarize

| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId

Stage 7: where

| where Active == true and ExpirationDateTime > now()

Stage 8: 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 9: where

where SQLSecurityAuditEvents_TimeGenerated < ExpirationDateTime

Stage 10: summarize

summarize SQLSecurityAuditEvents_TimeGenerated by IndicatorId, ClientIP

Stage 11: project

project Action, ActivityGroupNames, Application, ClientIP, ConfidenceScore, Description, EmailSourceIpAddress, ExpirationDateTime, HostName, IndicatorId, NetworkDestinationIP, NetworkIP, NetworkSourceIP, ResourceId, SQLSecurityAuditEvents_TimeGenerated, TI_ipEntity, ThreatType, Type, Url

Stage 12: 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
ConfidenceScoreproject
Descriptionproject
EmailSourceIpAddressproject
ExpirationDateTimeproject
HostNameproject
IndicatorIdproject
NetworkDestinationIPproject
NetworkIPproject
NetworkSourceIPproject
ResourceIdproject
SQLSecurityAuditEvents_TimeGeneratedproject
TI_ipEntityproject
ThreatTypeproject
Typeproject
Urlproject
timestampextend