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

Tactic	Techniques
Stealth	`T1070` Indicator Removal

Telemetry coverage

Platform	Record / event type
AWS	CloudTrail event `DeleteTrail`: Deletes a CloudTrail trail, permanently stopping the delivery of log files for that trail to its configured S3 bucket.
AWS	CloudTrail event `StopLogging`: Suspends CloudTrail logging for a trail, halting the delivery of new log files while preserving the trail configuration.
AWS	CloudTrail event `UpdateTrail`: Updates the settings of an existing CloudTrail trail, such as its S3 bucket, SNS topic, or log file validation configuration.
AWS	CloudTrail event `DeleteFlowLogs`: Deletes one or more VPC flow logs.
AWS	CloudTrail event `DeleteEventBus`: Deletes the specified custom event bus or partner event bus.

Rules detecting the same action

These rules filter on the same operation.

A CloudTrail Was Created or Updated (Panther)
Account Security Configuration Changed (Panther)
ASL AWS Defense Evasion Delete Cloudtrail (Splunk)
ASL AWS Defense Evasion Stop Logging Cloudtrail (Splunk)
ASL AWS Defense Evasion Update Cloudtrail (Splunk)
AWS Lateral Movement from Kubernetes SA via AssumeRoleWithWebIdentity (Elastic)
AWS VPC Flow Logs Deleted (Sigma)
AWS VPC Flow Logs Removed (Panther)

Rule body

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

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`EventName`	in	`DeleteEventBus` `DeleteFlowLogs` `DeleteTrail` `StopLogging` `UpdateTrail`	`field:"aws::eventName" kind:in`

Output fields

These fields are emitted when the rule matches.

Field	Source
`AWSRegion`	`summarize`
`AccountName`	`summarize`
`AccountUPNSuffix`	`summarize`
`EndTimeUtc`	`summarize`
`EventName`	`summarize`
`EventSource`	`summarize`
`EventTypeName`	`summarize`
`RecipientAccountId`	`summarize`
`SessionMfaAuthenticated`	`summarize`
`SourceIpAddress`	`summarize`
`StartTimeUtc`	`summarize`
`UserAgent`	`summarize`
`UserIdentityAccountId`	`summarize`
`UserIdentityPrincipalid`	`summarize`
`UserIdentityUserName`	`summarize`