Detection rules › Kusto

TI Map IP Entity to DeviceNetworkEvents

Severity
medium
Time window
14d
Group by
DeviceName, IndicatorId, RemoteIP, TI_ipEntity
Source
github.com/Azure/Azure-Sentinel

'Identifies a match in DeviceNetworkEvents Event data from any IP Indicator from TI.'

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1071 Application Layer Protocol

Rule body kusto

id: b2df4979-d34a-48b3-a7d9-f473a4bf8058
name: TI Map IP Entity to DeviceNetworkEvents
description: |
  'Identifies a match in DeviceNetworkEvents Event data from any IP Indicator from TI.'
severity: Medium
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceNetworkEvents
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let DeviceNetworkEvents_ = DeviceNetworkEvents
  | where isnotempty(RemoteIP)
  | where TimeGenerated > ago(dt_lookBack)
  | where ActionType !has "ConnectionFailed"
  | extend isPrivate = ipv4_is_private(RemoteIP)
  | where isPrivate != true;
  let IPs = DeviceNetworkEvents_ | distinct RemoteIP | summarize make_list(RemoteIP);
  ThreatIntelligenceIndicator
  | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend TI_ipEntity = coalesce(NetworkIP, EmailSourceIpAddress, NetworkDestinationIP, NetworkSourceIP)
  | where TI_ipEntity in (IPs)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now()
  | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
  | join kind=innerunique (DeviceNetworkEvents_) on $left.TI_ipEntity == $right.RemoteIP
  | summarize TimeGenerated = arg_max(TimeGenerated, *) by IndicatorId, TI_ipEntity, DeviceName
  // DeviceName, TI_ipEntity, RemoteUrl, InitiatingProcessAccountUpn
  | extend timestamp = TimeGenerated, Name = tostring(split(InitiatingProcessAccountUpn, '@', 0)[0]), UPNSuffix = tostring(split(InitiatingProcessAccountUpn, '@', 1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: TI_ipEntity
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: RemoteUrl
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: DeviceName
version: 1.0.1
kind: Scheduled

Stages and Predicates

Parameters

let dt_lookBack = 1h;
let ioc_lookBack = 14d;

Let binding: DeviceNetworkEvents_

let DeviceNetworkEvents_ = DeviceNetworkEvents
| where isnotempty(RemoteIP)
| where TimeGenerated > ago(dt_lookBack)
| where ActionType !has "ConnectionFailed"
| extend isPrivate = ipv4_is_private(RemoteIP)
| where isPrivate != true;

Derived from dt_lookBack.

Let binding: IPs

let IPs = DeviceNetworkEvents_ | distinct RemoteIP | summarize make_list(RemoteIP);

Derived from DeviceNetworkEvents_.

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

| extend TI_ipEntity = coalesce(NetworkIP, EmailSourceIpAddress, NetworkDestinationIP, NetworkSourceIP)

Stage 5: where

| where TI_ipEntity in (IPs)

References IPs (defined above).

Stage 6: summarize

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

Stage 7: where

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

Stage 8: where

| where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"

Stage 9: join

| join kind=innerunique (DeviceNetworkEvents_) on $left.TI_ipEntity == $right.RemoteIP

Stage 10: summarize

| summarize TimeGenerated = arg_max(TimeGenerated, *) by IndicatorId, TI_ipEntity, DeviceName

Stage 11: extend

| extend timestamp = TimeGenerated, Name = tostring(split(InitiatingProcessAccountUpn, '@', 0)[0]), UPNSuffix = tostring(split(InitiatingProcessAccountUpn, '@', 1)[0])

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
DescriptioncontainsState: falsepos;
DescriptioncontainsState: inactive;
ActionTypematchConnectionFailed

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.

FieldKindValues
Activeeq
  • true transforms: cased corpus 68 (kusto 68)
EmailSourceIpAddressis_not_null
  • (no value, null check)
NetworkDestinationIPis_not_null
  • (no value, null check)
NetworkIPis_not_null
  • (no value, null check)
NetworkSourceIPis_not_null
  • (no value, null check)
RemoteIPis_not_null
  • (no value, null check)
TI_ipEntityin
  • IPs transforms: cased corpus 2 (kusto 2)
isPrivatene
  • true transforms: cased corpus 2 (kusto 2)

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.

FieldSource
DeviceNamesummarize
IndicatorIdsummarize
TI_ipEntitysummarize
TimeGeneratedsummarize
Nameextend
UPNSuffixextend
timestampextend