TI Map URL Entity to DeviceNetworkEvents

Severity: medium
Time window: 14d
Group by: IndicatorId, RemoteUrl, Url
Source: github.com/Azure/Azure-Sentinel

This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in DeviceNetworkEvents.

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1071` Application Layer Protocol

Telemetry coverage

Platform	Record / event type
Microsoft Defender for Endpoint	`DeviceNetworkEvents` action `any`: Network activity

Rule body

id: 6ddbd892-a9be-47be-bab7-521241695bd6
name: TI Map URL Entity to DeviceNetworkEvents
description: |
  'This query identifies any URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in DeviceNetworkEvents.'
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(RemoteUrl)
    | where TimeGenerated >= ago(dt_lookBack)
    | where ActionType !has "ConnectionFailed"
    | extend RemoteUrl = tolower(RemoteUrl)
    | project-rename DeviceNetworkEvents_TimeGenerated = TimeGenerated;
  let DeviceNetworkEventUrls = DeviceNetworkEvents_
    | distinct Url = RemoteUrl
    | summarize make_list(Url);
  ThreatIntelligenceIndicator
  | where isnotempty(Url)
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend Url = tolower(Url)
  | where Url in (DeviceNetworkEventUrls)
  | 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.Url == $right.RemoteUrl
  | where DeviceNetworkEvents_TimeGenerated < ExpirationDateTime
  | summarize DeviceNetworkEvents_TimeGenerated = arg_max(DeviceNetworkEvents_TimeGenerated, *) by IndicatorId, Url
  | project DeviceNetworkEvents_TimeGenerated, IndicatorId, Url, ConfidenceScore, Description, ThreatType, Tags, TrafficLightProtocolLevel, ActionType, DeviceId, DeviceName, InitiatingProcessAccountUpn, InitiatingProcessCommandLine, RemoteIP, RemotePort
  | extend Name = tostring(split(InitiatingProcessAccountUpn, '@', 0)[0]), UPNSuffix = tostring(split(InitiatingProcessAccountUpn, '@', 1)[0])
  | extend timestamp = DeviceNetworkEvents_TimeGenerated, UserPrincipalName = InitiatingProcessAccountUpn
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
  - entityType: Process
    fieldMappings:
      - identifier: CommandLine
        columnName: InitiatingProcessCommandLine
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

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

Let binding: `DeviceNetworkEvents_` used in Stages 1, 11

let DeviceNetworkEvents_ = DeviceNetworkEvents
  | where isnotempty(RemoteUrl)
  | where TimeGenerated >= ago(dt_lookBack)
  | where ActionType !has "ConnectionFailed"
  | extend RemoteUrl = tolower(RemoteUrl)
  | project-rename DeviceNetworkEvents_TimeGenerated = TimeGenerated;

Let binding: `DeviceNetworkEventUrls` used in Stages 2, 7

let DeviceNetworkEventUrls = DeviceNetworkEvents_
  | distinct Url = RemoteUrl
  | summarize make_list(Url);

Stage 1: `source`

let DeviceNetworkEvents_

Stage 2: `source`

let DeviceNetworkEventUrls

Stage 3: `source`

ThreatIntelligenceIndicator

Stage 4: `where`

where isnotempty(Url)

Stage 5: `where`

where TimeGenerated >= ago(1209600s)

Stage 6: `extend`

extend Url

Stage 7: `where`

where Url =~ "DeviceNetworkEventUrls"

Stage 8: `summarize`

summarize LatestIndicatorTime by IndicatorId

Stage 9: `where`

where Active =~ true

Stage 10: `where`

where not (Description contains "State: falsepos;") and not (Description contains "State: inactive;")

Stage 11: `join`

join kind=innerunique (DeviceNetworkEvents_) on Url, RemoteUrl

Stage 12: `where`

where DeviceNetworkEvents_TimeGenerated < ExpirationDateTime

Stage 13: `summarize`

summarize DeviceNetworkEvents_TimeGenerated by IndicatorId, Url

Stage 14: `project`

project ActionType, ConfidenceScore, Description, DeviceId, DeviceName, DeviceNetworkEvents_TimeGenerated, IndicatorId, InitiatingProcessAccountUpn, InitiatingProcessCommandLine, RemoteIP, RemotePort, Tags, ThreatType, TrafficLightProtocolLevel, Url

Stage 15: `extend`

extend Name, UPNSuffix

Stage 16: `extend`

extend UserPrincipalName, timestamp

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Description`	contains	`State: falsepos;`	`excludes:Description` `field:"Description" value:"State: falsepos;"`
`Description`	contains	`State: inactive;`	`excludes:Description` `field:"Description" value:"State: inactive;"`
`ActionType`	match	`ConnectionFailed`	`excludes:ActionType` `field:"ActionType" value:"ConnectionFailed"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Active`	eq	`true` corpus 70 (kusto 70)	`field:"Active" kind:eq value:"true"`
`DeviceNetworkEvents_TimeGenerated`	cross_field_compare	`ExpirationDateTime` transforms: `op:lt` corpus 2 (kusto 2)	`field:"DeviceNetworkEvents_TimeGenerated" kind:cross_field_compare value:"ExpirationDateTime"`
`RemoteUrl`	is_not_null	(no value, null check)	`field:"DestinationHostname" kind:is_not_null`
`Url`	in	`DeviceNetworkEventUrls` corpus 2 (kusto 2)	`field:"Url" kind:in value:"DeviceNetworkEventUrls"`
`Url`	is_not_null	(no value, null check)	`field:"Url" kind:is_not_null`

Output fields

These fields are emitted when the rule matches.

Field	Source
`ActionType`	`project`
`ConfidenceScore`	`project`
`Description`	`project`
`DeviceId`	`project`
`DeviceName`	`project`
`DeviceNetworkEvents_TimeGenerated`	`project`
`IndicatorId`	`project`
`InitiatingProcessAccountUpn`	`project`
`InitiatingProcessCommandLine`	`project`
`RemoteIP`	`project`
`RemotePort`	`project`
`Tags`	`project`
`ThreatType`	`project`
`TrafficLightProtocolLevel`	`project`
`Url`	`project`
`Name`	`extend`
`UPNSuffix`	`extend`
`UserPrincipalName`	`extend`
`timestamp`	`extend`

TI Map URL Entity to DeviceNetworkEvents

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Parameters

Let binding: DeviceNetworkEvents_ used in Stages 1, 11

Let binding: DeviceNetworkEventUrls used in Stages 2, 7

Stage 1: source

Stage 2: source

Stage 3: source

Stage 4: where

Stage 5: where

Stage 6: extend

Stage 7: where

Stage 8: summarize

Stage 9: where

Stage 10: where

Stage 11: join

Stage 12: where

Stage 13: summarize

Stage 14: project

Stage 15: extend

Stage 16: extend