Modification or Deletion of an AWS RDS Cluster

Status: experimental
Severity: high
Log source: product aws, service cloudtrail
Author: Ivan Saakov
Source: github.com/SigmaHQ/sigma

Detects modifications to an RDS cluster or its deletion, which may indicate potential data exfiltration attempts, unauthorized access, or exposure of sensitive information.

MITRE ATT&CK coverage

Tactic	Techniques
Exfiltration	`T1020` Automated Exfiltration

Event coverage

Provider	Event
AWS-rds	DeleteDBCluster
AWS-rds	ModifyDBCluster

Rules detecting the same action

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

AWS RDS DB Instance or Cluster Deleted (Elastic)
AWS RDS DB Instance or Cluster Deletion Protection Disabled (Elastic)
AWS RDS DB Instance or Cluster Password Modified (Elastic)
AWS RDS Deletion Protection Disabled (Panther)
AWS RDS Instance Modified to be Publicly Accessible (Panther)
AWS RDS Instance or Cluster Deleted (Panther)

Rule body yaml

title: Modification or Deletion of an AWS RDS Cluster
id: 457cc9ac-d8e6-4d1d-8c0e-251d0f11a74c
status: experimental
description: Detects modifications to an RDS cluster or its deletion, which may indicate potential data exfiltration attempts, unauthorized access, or exposure of sensitive information.
references:
    - https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_ModifyDBCluster.html
    - https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_DeleteDBCluster.html
    - https://cloud.hacktricks.xyz/pentesting-cloud/aws-security/aws-privilege-escalation/aws-rds-privesc#rds-modifydbinstance
author: Ivan Saakov
date: 2024-12-06
tags:
    - attack.exfiltration
    - attack.t1020
logsource:
    product: aws
    service: cloudtrail
detection:
    selection:
        eventSource: rds.amazonaws.com
        eventName:
            - ModifyDBCluster
            - DeleteDBCluster
    condition: selection
falsepositives:
    - Verify if the modification or deletion was performed by an authorized administrator.
    - Confirm if the modification or deletion was part of a planned change or maintenance activity.
level: high

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    eventSource: rds.amazonaws.com
    eventName:
        - ModifyDBCluster
        - DeleteDBCluster

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
`eventName`	eq	`DeleteDBCluster` `ModifyDBCluster`
`eventSource`	eq	`rds.amazonaws.com`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`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)

Modification or Deletion of an AWS RDS Cluster

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Indicators

Keyboard shortcuts

Search operators

Modification or Deletion of an AWS RDS Cluster

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`