AWS RDS Instance or Cluster Rebooted

Severity: medium
Log types: AWS.CloudTrail
Tags: AWS, Impact, Availability, Endpoint Denial of Service, RDS
Reference: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_RebootInstance.html
Source: github.com/panther-labs/panther-analysis

Detects when RDS instances, clusters, or shard groups are rebooted. Unexpected reboots cause service disruption and may indicate DoS attempts, unauthorized testing, or operational issues requiring investigation.

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1499` Endpoint Denial of Service

Rule body yaml

AnalysisType: rule
Filename: aws_rds_instance_rebooted.py
RuleID: "AWS.RDS.InstanceRebooted"
DisplayName: "AWS RDS Instance or Cluster Rebooted"
Enabled: true
LogTypes:
  - AWS.CloudTrail
Tags:
  - AWS
  - Impact
  - Availability
  - Endpoint Denial of Service
  - RDS
Severity: Medium
Description: >
  Detects when RDS instances, clusters, or shard groups are rebooted. Unexpected reboots
  cause service disruption and may indicate DoS attempts, unauthorized testing, or
  operational issues requiring investigation.
Runbook: |
  1. Find all database reboot events by the user ARN in the past 24 hours to identify bulk reboot patterns
  2. Check if this user has rebooted databases in the past 90 days to determine if this is normal behavior
  3. Look for database modification events from this user in the 30 minutes before the reboot
Reference: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_RebootInstance.html
Reports:
  MITRE ATT&CK:
    - TA0040:T1499  # Endpoint Denial of Service
DedupPeriodMinutes: 60
SummaryAttributes:
  - eventName
  - userIdentity:principalId
  - requestParameters:dBInstanceIdentifier
  - requestParameters:dBClusterIdentifier
  - p_any_aws_account_ids
Threshold: 1
Tests:
  - Name: DB Instance Rebooted
    ExpectedResult: true
    Log:
      eventVersion: "1.08"
      userIdentity:
        type: AssumedRole
        principalId: "AIDAI23HXS3EXAMPLE:admin"
        arn: "arn:aws:sts::123456789012:assumed-role/DBARole/admin"
        accountId: "123456789012"
        accessKeyId: "ASIAIOSFODNN7EXAMPLE"
      eventTime: "2024-01-18T02:00:00Z"
      eventSource: rds.amazonaws.com
      eventName: RebootDBInstance
      awsRegion: us-east-1
      sourceIPAddress: "10.0.1.100"
      userAgent: "console.amazonaws.com"
      requestParameters:
        dBInstanceIdentifier: "production-mysql"
        forceFailover: false
      responseElements:
        dBInstanceIdentifier: "production-mysql"
        dBInstanceStatus: "rebooting"
      requestID: "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
      eventID: "f1e2d3c4-b5a6-7890-1234-567890abcdef"
      readOnly: false
      eventType: AwsApiCall
      managementEvent: true
      recipientAccountId: "123456789012"
      eventCategory: Management

  - Name: DB Cluster Rebooted with Failover
    ExpectedResult: true
    Log:
      eventVersion: "1.08"
      userIdentity:
        type: IAMUser
        principalId: "AIDAI23HXS3EXAMPLE"
        arn: "arn:aws:iam::123456789012:user/operator"
        accountId: "123456789012"
        accessKeyId: "AKIAIOSFODNN7EXAMPLE"
        userName: operator
      eventTime: "2024-01-18T02:00:00Z"
      eventSource: rds.amazonaws.com
      eventName: RebootDBCluster
      awsRegion: us-west-2
      sourceIPAddress: "203.0.113.100"
      userAgent: "aws-cli/2.13.0"
      requestParameters:
        dBClusterIdentifier: "aurora-cluster-prod"
        forceFailover: true
      responseElements:
        dBClusterIdentifier: "aurora-cluster-prod"
        status: "rebooting"
      requestID: "b2c3d4e5-f6a7-8901-bcde-f1234567890a"
      eventID: "g2f3e4d5-c6b7-8901-2345-678901bcdefg"
      readOnly: false
      eventType: AwsApiCall
      managementEvent: true
      recipientAccountId: "123456789012"
      eventCategory: Management

  - Name: Reboot Failed
    ExpectedResult: false
    Log:
      eventVersion: "1.08"
      userIdentity:
        type: IAMUser
        principalId: "AIDAI23HXS3EXAMPLE"
        arn: "arn:aws:iam::123456789012:user/developer"
        accountId: "123456789012"
        accessKeyId: "AKIAIOSFODNN7EXAMPLE"
        userName: developer
      eventTime: "2024-01-18T02:00:00Z"
      eventSource: rds.amazonaws.com
      eventName: RebootDBInstance
      awsRegion: us-east-1
      sourceIPAddress: "10.0.2.100"
      userAgent: "aws-cli/2.13.0"
      requestParameters:
        dBInstanceIdentifier: "production-db"
      errorCode: InvalidDBInstanceState
      errorMessage: "Cannot reboot DB instance in current state"
      requestID: "c3d4e5f6-a7b8-9012-cdef-1234567890ab"
      eventID: "h3g4f5e6-d7c8-9012-3456-789012cdefgh"
      readOnly: false
      eventType: AwsApiCall
      managementEvent: true
      recipientAccountId: "123456789012"
      eventCategory: Management

  - Name: Different RDS Event
    ExpectedResult: false
    Log:
      eventVersion: "1.08"
      userIdentity:
        type: AssumedRole
        principalId: "AIDAI23HXS3EXAMPLE:user"
        arn: "arn:aws:sts::123456789012:assumed-role/Admin/user"
        accountId: "123456789012"
      eventTime: "2024-01-18T02:00:00Z"
      eventSource: rds.amazonaws.com
      eventName: StartDBInstance
      awsRegion: us-east-1
      sourceIPAddress: "10.0.1.100"
      requestParameters:
        dBInstanceIdentifier: "dev-database"
      requestID: "d4e5f6a7-b8c9-0123-def0-1234567890bc"
      eventID: "i4h5g6f7-e8d9-0123-4567-890123defghi"
      readOnly: false
      eventType: AwsApiCall
      managementEvent: true
      recipientAccountId: "123456789012"
      eventCategory: Management

Detection logic

Condition

eventSource eq "rds.amazonaws.com"
eventName in ["RebootDBInstance", "RebootDBCluster", "RebootDBShardGroup"]
errorCode is_null

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
`errorCode`	is_null	(no value, null check)
`eventName`	in	`RebootDBCluster` `RebootDBInstance` `RebootDBShardGroup`
`eventSource`	eq	`rds.amazonaws.com`

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
`eventName`
`eventSource`
`awsRegion`
`recipientAccountId`
`sourceIPAddress`
`userAgent`
`userIdentity`
`dBInstanceIdentifier`	`requestParameters.dBInstanceIdentifier`
`userName`	`userIdentity.userName`

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`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)