Detection rules › Kusto
GSA - TI URL Entity
This query identifies URL indicators of compromise (IOCs) from threat intelligence (TI) by searching for matches in GSA NetworkAccessTraffic.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1071 Application Layer Protocol |
Rule body kusto
id: 347c6cb3-33d2-4753-b7f6-eab946a8cd51
name: 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
status: Available
requiredDataConnectors:
- connectorId: AzureActiveDirectory
dataTypes:
- NetworkAccessTrafficLogs
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1071
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
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: UserPrincipalName
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SourceIp
- entityType: URL
fieldMappings:
- identifier: Url
columnName: DestinationUrl
- entityType: Process
fieldMappings:
- identifier: CommandLine
columnName: InitiatingProcessName
version: 1.0.1
kind: Scheduled
Stages and Predicates
Parameters
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
Let binding: GSANetworkAccessTraffic_
let GSANetworkAccessTraffic_ = NetworkAccessTraffic
| where TimeGenerated >= ago(dt_lookBack)
| where TrafficType == "internet"
| extend DestinationUrlToLower = tolower(DestinationUrl)
| project-rename GSANetworkAccessTraffic_TimeGenerated = TimeGenerated;
Derived from dt_lookBack.
Let binding: GSANetworkAccessTrafficUrls
let GSANetworkAccessTrafficUrls = GSANetworkAccessTraffic_
| where isnotempty(DestinationUrl)
| extend Url = tolower(DestinationUrl)
| distinct Url;
Derived from GSANetworkAccessTraffic_.
Stage 1: source
ThreatIntelIndicators
Stage 2: extend
| extend IndicatorType = replace(@'[\[\]"]', "", tostring(split(ObservableKey, ":", 0)))
Stage 3: where
| where IndicatorType == "url"
Stage 4: extend
| extend Url = ObservableValue
Stage 5: extend
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
Stage 6: where
| where TimeGenerated >= ago(ioc_lookBack)
Stage 7: extend
| extend Url = tolower(Url)
Stage 8: where
| where Url in (GSANetworkAccessTrafficUrls)
References GSANetworkAccessTrafficUrls (defined above).
Stage 9: summarize
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
Stage 10: where
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
Stage 11: extend
| extend Description = tostring(parse_json(Data).description)
Stage 12: where
| where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
Stage 13: project-reorder
| project-reorder *, Tags, TrafficLightProtocolLevel, Url, Type
Stage 14: join
| join kind=innerunique (GSANetworkAccessTraffic_) on $left.Url == $right.DestinationUrlToLower
Stage 15: where
| where isempty(ValidUntil) or GSANetworkAccessTraffic_TimeGenerated < ValidUntil
Stage 16: extend
| extend GSAThreatType = ThreatType
Stage 17: summarize
| summarize GSANetworkAccessTraffic_TimeGenerated = arg_max(GSANetworkAccessTraffic_TimeGenerated, *) by Id, DestinationUrl
Stage 18: project-reorder
| project-reorder *,
Tags,
Confidence,
TrafficLightProtocolLevel,
Type,
UserPrincipalName,
UserId,
DeviceId,
InitiatingProcessName,
GSAThreatType,
DestinationIp,
DestinationFqdn,
DestinationUrl,
DestinationPort,
SourceIp,
SourcePort,
HttpUserAgent
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
Description | contains | State: falsepos; |
Description | contains | State: inactive; |
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.
| Field | Kind | Values |
|---|---|---|
GSANetworkAccessTraffic_TimeGenerated | lt |
|
IndicatorType | eq |
|
TrafficType | eq |
|
Url | in |
|
ValidUntil | is_null |
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.
| Field | Source |
|---|---|
DestinationUrl | summarize |
GSANetworkAccessTraffic_TimeGenerated | summarize |
Id | summarize |