Detection rules › Kusto
ThreatConnect TI map IP entity to Network Session Events (ASIM Network Session schema)
ThreatConnect Specific: This rule identifies a match Network Sessions for which the source or destination IP address is a known IoC. This analytic rule uses ASIM and supports any built-in or custom source that supports the ASIM NetworkSession schema
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1071 Application Layer Protocol |
Rule body kusto
id: ee1fd303-2081-47b7-8f02-e38bfd0868e6
name: ThreatConnect TI map IP entity to Network Session Events (ASIM Network Session schema)
version: 1.0.2
kind: Scheduled
description: |-
ThreatConnect Specific:
This rule identifies a match Network Sessions for which the source or destination IP address is a known IoC.
This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM NetworkSession schema
severity: Medium
requiredDataConnectors:
- connectorId: ThreatIntelligence
dataTypes:
- ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1071
query: |
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_TI = materialize (
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where ExpirationDateTime > now() and Active == true
| where SourceSystem startswith "ThreatConnect-"
| extend TI_ipEntity = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP,EmailSourceIpAddress,"NO_IP")
| where TI_ipEntity != "NO_IP"
);
IP_TI
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique
(
_Im_NetworkSession (starttime=ago(dt_lookBack))
| where isnotempty(SrcIpAddr)
| summarize imNWS_mintime=min(TimeGenerated), imNWS_maxtime=max(TimeGenerated) by SrcIpAddr, DstIpAddr, Dvc, EventProduct, EventVendor
| lookup (IP_TI | project TI_ipEntity, Active) on $left.SrcIpAddr == $right.TI_ipEntity
| project-rename SrcMatch = Active
| lookup (IP_TI | project TI_ipEntity, Active) on $left.DstIpAddr == $right.TI_ipEntity
| project-rename DstMatch = Active
| where SrcMatch or DstMatch
| extend
IoCIP = iff(SrcMatch, SrcIpAddr, DstIpAddr),
IoCDirection = iff(SrcMatch, "Source", "Destination")
)on $left.TI_ipEntity == $right.IoCIP
| where imNWS_mintime < ExpirationDateTime
| project imNWS_mintime, imNWS_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SrcIpAddr, DstIpAddr, IoCDirection, IoCIP, Dvc, EventVendor, EventProduct
suppressionEnabled: false
incidentConfiguration:
createIncident: true
groupingConfiguration:
enabled: true
reopenClosedIncident: false
lookbackDuration: 4h
matchingMethod: AllEntities
eventGroupingSettings:
aggregationKind: SingleAlert
alertDetailsOverride:
alertDisplayNameFormat: A network session {{IoCDirection}} address {{IoCIP}} matched an IoC.
alertDescriptionFormat: The {{IoCDirection}} address {{IoCIP}} of a network session matched a known indicator of compromise of {{ThreatType}}. Consult the threat intelligence blead for more information on the indicator.
customDetails:
IndicatorId: IndicatorId
IoCConfidenceScore: ConfidenceScore
IoCDescription: Description
IoCExpirationTime: ExpirationDateTime
EventEndTime: imNWS_maxtime
ActivityGroupNames: ActivityGroupNames
ThreatType: ThreatType
IoCIPDirection: IoCDirection
EventStartTime: imNWS_mintime
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IoCIP
suppressionDuration: 1h
Stages and Predicates
Parameters
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
The stages below define let IP_TI (the rule's main pipeline source).
Stage 1: source
ThreatIntelligenceIndicator
Stage 2: where
| where TimeGenerated >= ago(ioc_lookBack)
Stage 3: summarize
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
Stage 4: where
| where ExpirationDateTime > now() and Active == true
Stage 5: where
| where SourceSystem startswith "ThreatConnect-"
Stage 6: extend
| extend TI_ipEntity = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP,EmailSourceIpAddress,"NO_IP")
Stage 7: where
| where TI_ipEntity != "NO_IP"
The stages below run on IP_TI (the outer pipeline).
Stage 8: join
IP_TI
| join kind=innerunique
(
_Im_NetworkSession (starttime=ago(dt_lookBack))
| where isnotempty(SrcIpAddr)
| summarize imNWS_mintime=min(TimeGenerated), imNWS_maxtime=max(TimeGenerated) by SrcIpAddr, DstIpAddr, Dvc, EventProduct, EventVendor
| lookup (IP_TI | project TI_ipEntity, Active) on $left.SrcIpAddr == $right.TI_ipEntity
| project-rename SrcMatch = Active
| lookup (IP_TI | project TI_ipEntity, Active) on $left.DstIpAddr == $right.TI_ipEntity
| project-rename DstMatch = Active
| where SrcMatch or DstMatch
| extend
IoCIP = iff(SrcMatch, SrcIpAddr, DstIpAddr),
IoCDirection = iff(SrcMatch, "Source", "Destination")
)on $left.TI_ipEntity == $right.IoCIP
Stage 9: where
| where imNWS_mintime < ExpirationDateTime
Stage 10: project
| project imNWS_mintime, imNWS_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, SrcIpAddr, DstIpAddr, IoCDirection, IoCIP, Dvc, EventVendor, EventProduct
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 |
|---|---|---|
Active | eq |
|
SourceSystem | starts_with |
|
SrcIpAddr | is_not_null | |
TI_ipEntity | ne |
|
imNWS_mintime | lt |
|
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 |
|---|---|
ActivityGroupNames | project |
ConfidenceScore | project |
Description | project |
DstIpAddr | project |
Dvc | project |
EventProduct | project |
EventVendor | project |
ExpirationDateTime | project |
IndicatorId | project |
IoCDirection | project |
IoCIP | project |
SrcIpAddr | project |
ThreatType | project |
imNWS_maxtime | project |
imNWS_mintime | project |