Detection rules › Kusto

AWSCloudTrail - Changes made to AWS CloudTrail logs

Status
available
Severity
low
Time window
1d
Group by
AWSRegion, AccountName, AccountUPNSuffix, EventName, EventSource, EventTypeName, RecipientAccountId, SessionMfaAuthenticated, SourceIpAddress, UserAgent, UserIdentityAccountId, UserIdentityPrincipalid, UserIdentityUserName
Source
github.com/Azure/Azure-Sentinel

Identifies manipulation of AWS CloudTrail, CloudWatch/EventBridge, or VPC Flow Logs that can indicate defense evasion. This alert identifies any manipulation of AWS CloudTrail, Cloudwatch/EventBridge or VPC Flow logs. More Information: AWS CloudTrail API: https://docs.aws.amazon.com/awscloudtrail/latest/APIReference/API_Operations.html AWS Cloudwatch/Eventbridge API: https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_Operations.html AWS DelteteFlowLogs API : https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DeleteFlowLogs.html '

MITRE ATT&CK coverage

TacticTechniques
StealthT1070 Indicator Removal

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Rule body kusto

id: 610d3850-c26f-4f20-8d86-f10fdf2425f5
name: AWSCloudTrail - Changes made to AWS CloudTrail logs
description: |
  Identifies manipulation of AWS CloudTrail, CloudWatch/EventBridge, or VPC Flow Logs that can indicate defense evasion.
  This alert identifies any manipulation of AWS CloudTrail, Cloudwatch/EventBridge or VPC Flow logs.
  More Information: AWS CloudTrail API: https://docs.aws.amazon.com/awscloudtrail/latest/APIReference/API_Operations.html 
  AWS Cloudwatch/Eventbridge API: https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_Operations.html 
  AWS DelteteFlowLogs API : https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DeleteFlowLogs.html ' 
severity: Low
status: Available
requiredDataConnectors:
  - connectorId: AWS
    dataTypes:
      - AWSCloudTrail
  - connectorId: AWSS3
    dataTypes:
      - AWSCloudTrail
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1070
query: |
  let EventNameList = dynamic(["UpdateTrail","DeleteTrail","StopLogging","DeleteFlowLogs","DeleteEventBus"]);
  AWSCloudTrail
  | where EventName in~ (EventNameList)
  | extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
  | extend UserName = tostring(split(UserIdentityArn, '/')[-1])
  | extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
  | extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
    AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")
  | summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventName, EventTypeName, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,
  UserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountName
      - identifier: UPNSuffix
        columnName: AccountUPNSuffix
      - identifier: CloudAppAccountId
        columnName: RecipientAccountId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SourceIpAddress
alertDetailsOverride:
  alertDisplayNameFormat: "AWS CloudTrail log manipulation detected by {{AccountName}} from {{SourceIpAddress}}"
  alertDescriptionFormat: "Event {{EventName}} occurred in {{AWSRegion}} for account {{RecipientAccountId}}"
customDetails:
  EventName: EventName
  EventTypeName: EventTypeName
  EventSource: EventSource
  AWSRegion: AWSRegion
  UserAgent: UserAgent
version: 1.0.5
kind: Scheduled

Stages and Predicates

Parameters

let EventNameList = dynamic(["UpdateTrail","DeleteTrail","StopLogging","DeleteFlowLogs","DeleteEventBus"]);

Stage 1: source

AWSCloudTrail

Stage 2: where

| where EventName in~ (EventNameList)

Stage 3: extend (4 consecutive steps)

| extend UserIdentityArn = iif(isempty(UserIdentityArn), tostring(parse_json(Resources)[0].ARN), UserIdentityArn)
| extend UserName = tostring(split(UserIdentityArn, '/')[-1])
| extend AccountName = case( UserIdentityPrincipalid == "Anonymous", "Anonymous", isempty(UserIdentityUserName), UserName, UserIdentityUserName)
| extend AccountName = iif(AccountName contains "@", tostring(split(AccountName, '@', 0)[0]), AccountName),
  AccountUPNSuffix = iif(AccountName contains "@", tostring(split(AccountName, '@', 1)[0]), "")

Stage 4: summarize

| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated) by EventName, EventTypeName, RecipientAccountId, AccountName, AccountUPNSuffix, UserIdentityAccountId, UserIdentityPrincipalid, UserAgent,
UserIdentityUserName, SessionMfaAuthenticated, SourceIpAddress, AWSRegion, EventSource

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.

FieldKindValues
EventNamein
  • DeleteEventBus
  • DeleteFlowLogs
  • DeleteTrail
  • StopLogging
  • UpdateTrail

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.

FieldSource
AWSRegionsummarize
AccountNamesummarize
AccountUPNSuffixsummarize
EndTimeUtcsummarize
EventNamesummarize
EventSourcesummarize
EventTypeNamesummarize
RecipientAccountIdsummarize
SessionMfaAuthenticatedsummarize
SourceIpAddresssummarize
StartTimeUtcsummarize
UserAgentsummarize
UserIdentityAccountIdsummarize
UserIdentityPrincipalidsummarize
UserIdentityUserNamesummarize