GSA - TI URL Entity

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Id	347c6cb3-33d2-4753-b7f6-eab946a8cd51
Rulename	GSA - TI URL Entity
Description	This query identifies URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in GSA NetworkAccessTraffic.
Severity	Medium
Tactics	CommandAndControl
Techniques	T1071
Required data connectors	AzureActiveDirectory
Kind	Scheduled
Query frequency	1h
Query period	14d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/GSA - TI URL Entity.yaml
Version	1.0.1
Arm template	347c6cb3-33d2-4753-b7f6-eab946a8cd51.json

KQL

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let GSANetworkAccessTraffic_ = NetworkAccessTraffic
| where TimeGenerated >= ago(dt_lookBack)
| where TrafficType  == "internet"
| extend DestinationUrlToLower = tolower(DestinationUrl)
| project-rename GSANetworkAccessTraffic_TimeGenerated = TimeGenerated;
let GSANetworkAccessTrafficUrls =
    GSANetworkAccessTraffic_
    | where isnotempty(DestinationUrl)
    | extend Url = tolower(DestinationUrl)
    | distinct Url;
ThreatIntelIndicators
  | extend IndicatorType = replace(@'[\[\]"]', "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "url"
  | extend Url = ObservableValue
  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend Url = tolower(Url)
  | where Url in (GSANetworkAccessTrafficUrls)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil))
  | extend Description = tostring(parse_json(Data).description)
  | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
  | project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
  | join kind=innerunique (GSANetworkAccessTraffic_) on $left.Url == $right.DestinationUrlToLower
  | where isempty(ValidUntil) or GSANetworkAccessTraffic_TimeGenerated < ValidUntil
  | extend GSAThreatType = ThreatType
| summarize GSANetworkAccessTraffic_TimeGenerated = arg_max(GSANetworkAccessTraffic_TimeGenerated, *) by Id, DestinationUrl
| project-reorder *,
    Tags,
    Confidence,
    TrafficLightProtocolLevel,
    Type,
    UserPrincipalName,
    UserId,
    DeviceId,
    InitiatingProcessName,
    GSAThreatType,
    DestinationIp,
    DestinationFqdn,
    DestinationUrl,
    DestinationPort,
    SourceIp,
    SourcePort,
    HttpUserAgent

YAML

entityMappings:
- fieldMappings:
  - columnName: UserPrincipalName
    identifier: Name
  entityType: Account
- fieldMappings:
  - columnName: SourceIp
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: DestinationUrl
    identifier: Url
  entityType: URL
- fieldMappings:
  - columnName: InitiatingProcessName
    identifier: CommandLine
  entityType: Process
triggerOperator: gt
tactics:
- CommandAndControl
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Global Secure Access/Analytic Rules/GSA - TI URL Entity.yaml
version: 1.0.1
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let GSANetworkAccessTraffic_ = NetworkAccessTraffic
  | where TimeGenerated >= ago(dt_lookBack)
  | where TrafficType  == "internet"
  | extend DestinationUrlToLower = tolower(DestinationUrl)
  | project-rename GSANetworkAccessTraffic_TimeGenerated = TimeGenerated;
  let GSANetworkAccessTrafficUrls =
      GSANetworkAccessTraffic_
      | where isnotempty(DestinationUrl)
      | extend Url = tolower(DestinationUrl)
      | distinct Url;
  ThreatIntelIndicators
    | extend IndicatorType = replace(@'[\[\]"]', "", tostring(split(ObservableKey, ":", 0)))
    | where IndicatorType == "url"
    | extend Url = ObservableValue
    | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
    | where TimeGenerated >= ago(ioc_lookBack)
    | extend Url = tolower(Url)
    | where Url in (GSANetworkAccessTrafficUrls)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
    | where IsActive and (ValidUntil > now() or isempty(ValidUntil))
    | extend Description = tostring(parse_json(Data).description)
    | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
    | project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
    | join kind=innerunique (GSANetworkAccessTraffic_) on $left.Url == $right.DestinationUrlToLower
    | where isempty(ValidUntil) or GSANetworkAccessTraffic_TimeGenerated < ValidUntil
    | extend GSAThreatType = ThreatType
  | summarize GSANetworkAccessTraffic_TimeGenerated = arg_max(GSANetworkAccessTraffic_TimeGenerated, *) by Id, DestinationUrl
  | project-reorder *,
      Tags,
      Confidence,
      TrafficLightProtocolLevel,
      Type,
      UserPrincipalName,
      UserId,
      DeviceId,
      InitiatingProcessName,
      GSAThreatType,
      DestinationIp,
      DestinationFqdn,
      DestinationUrl,
      DestinationPort,
      SourceIp,
      SourcePort,
      HttpUserAgent  
triggerThreshold: 0
relevantTechniques:
- T1071
queryPeriod: 14d
status: Available
severity: Medium
kind: Scheduled
name: GSA - TI URL Entity
queryFrequency: 1h
id: 347c6cb3-33d2-4753-b7f6-eab946a8cd51
description: |
    This query identifies URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in GSA NetworkAccessTraffic.
requiredDataConnectors:
- dataTypes:
  - NetworkAccessTrafficLogs
  connectorId: AzureActiveDirectory

ARM