Detection rules › Kusto
TI map IP entity to AWSCloudTrail
Identifies a match in AWSCloudTrail from any IP IOC from TI
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control |
Rule body
id: f110287e-1358-490d-8147-ed804b328514
name: TI map IP entity to AWSCloudTrail
description: |
Identifies a match in AWSCloudTrail from any IP IOC from TI
severity: Medium
requiredDataConnectors:
- connectorId: ThreatIntelligence
dataTypes:
- ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
dataTypes:
- ThreatIntelligenceIndicator
- connectorId: AWS
dataTypes:
- AWSCloudTrail
- connectorId: MicrosoftDefenderThreatIntelligence
dataTypes:
- ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1071
query: |
let dt_lookBack = 1h; // Look back 1 hour for AWSCloudTrail logs
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelligenceIndicator
// Filter out indicators without relevant IP address fields
| where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
| where TimeGenerated >= ago(ioc_lookBack)
// Select the IP entity based on availability of different IP fields
| extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
// Exclude local addresses using the ipv4_is_private operator and filtering out specific address prefixes
| where ipv4_is_private(TI_ipEntity) == false and TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now();
// Perform a join between IP indicators and AWSCloudTrail logs to identify potential malicious activity
IP_Indicators
// Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
| join kind=innerunique (
AWSCloudTrail
| where TimeGenerated >= ago(dt_lookBack)
| extend AWSCloudTrail_TimeGenerated = TimeGenerated // Rename time column for clarity
)
on $left.TI_ipEntity == $right.SourceIpAddress
// Filter out logs that occurred after the expiration of the corresponding indicator
| where AWSCloudTrail_TimeGenerated < ExpirationDateTime
// Group the results by IndicatorId and SourceIpAddress, and keep the log entry with the latest timestamp
| summarize AWSCloudTrail_TimeGenerated = arg_max(AWSCloudTrail_TimeGenerated, *) by IndicatorId, SourceIpAddress
// Select the desired output fields
| project AWSCloudTrail_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
TI_ipEntity, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserIdentityUserName, SourceIpAddress,
NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
// Rename the timestamp field
| extend timestamp = AWSCloudTrail_TimeGenerated
entityMappings:
- entityType: Account
fieldMappings:
- identifier: ObjectGuid
columnName: UserIdentityUserName
- entityType: IP
fieldMappings:
- identifier: Address
columnName: SourceIpAddress
- entityType: URL
fieldMappings:
- identifier: Url
columnName: Url
version: 1.4.2
kind: Scheduled
Stages and Predicates
Parameters
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_Indicators is inlined into the numbered stages below.
Stages 1 to 7 define let IP_Indicators (the rule's main pipeline source); stages 8 to 12 run on it.
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 (3 consecutive steps)
| extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
| extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
TI_ipEntity =if
isnotempty(NetworkIP)NetworkIPelse
NetworkDestinationIPStage 5: where
| where ipv4_is_private(TI_ipEntity) == false and TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
Stage 6: summarize
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
Stage 7: where
| where Active == true and ExpirationDateTime > now()
Stage 8: join
IP_Indicators
| join kind=innerunique (
AWSCloudTrail
| where TimeGenerated >= ago(dt_lookBack)
| extend AWSCloudTrail_TimeGenerated = TimeGenerated
)
on $left.TI_ipEntity == $right.SourceIpAddress
Stage 9: where
| where AWSCloudTrail_TimeGenerated < ExpirationDateTime
Stage 10: summarize
| summarize AWSCloudTrail_TimeGenerated = arg_max(AWSCloudTrail_TimeGenerated, *) by IndicatorId, SourceIpAddress
Stage 11: project
| project AWSCloudTrail_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
TI_ipEntity, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserIdentityUserName, SourceIpAddress,
NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
Stage 12: extend
| extend timestamp = AWSCloudTrail_TimeGenerated
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
TI_ipEntity | cidr_match | 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16, 127.0.0.0/8 | excludes:TI_ipEntity |
TI_ipEntity | starts_with | 127. | excludes:TI_ipEntity field:"TI_ipEntity" value:"127." |
TI_ipEntity | starts_with | :: | excludes:TI_ipEntity field:"TI_ipEntity" value:"::" |
TI_ipEntity | starts_with | fe80 | excludes:TI_ipEntity field:"TI_ipEntity" value:"fe80" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
AWSCloudTrail_TimeGenerated | cross_field_compare |
| field:"AWSCloudTrail_TimeGenerated" kind:cross_field_compare value:"ExpirationDateTime" |
Active | eq |
| field:"Active" kind:eq value:"true" |
EmailSourceIpAddress | is_not_null | field:"EmailSourceIpAddress" kind:is_not_null | |
NetworkDestinationIP | is_not_null | field:"NetworkDestinationIP" kind:is_not_null | |
NetworkIP | is_not_null | field:"NetworkIP" kind:is_not_null | |
NetworkSourceIP | is_not_null | field:"NetworkSourceIP" kind:is_not_null |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
AWSCloudTrail_TimeGenerated | project |
ActivityGroupNames | project |
ConfidenceScore | project |
Description | project |
EmailSourceIpAddress | project |
EventName | project |
EventTypeName | project |
ExpirationDateTime | project |
IndicatorId | project |
NetworkDestinationIP | project |
NetworkIP | project |
NetworkSourceIP | project |
SourceIpAddress | project |
TI_ipEntity | project |
ThreatType | project |
Type | project |
Url | project |
UserIdentityAccountId | project |
UserIdentityPrincipalid | project |
UserIdentityUserName | project |
timestamp | extend |