AWS VPC Flow Logs Removed

Status: Experimental
Severity: informational
Compliance: Stratus Red Team aws.defense-evasion.vpc-remove-flow-logs
Log types: AWS.CloudTrail
Tags: AWS, Cloudtrail, Defense Evasion, Impair Defenses, Disable or Modify Cloud Logs, Defense Evasion:Impair Defenses, Security Control
Reference: https://stratus-red-team.cloud/attack-techniques/AWS/aws.defense-evasion.vpc-remove-flow-logs/
Source: github.com/panther-labs/panther-analysis

Detects when logs for a VPC have been removed.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1562.008` Impair Defenses: Disable or Modify Cloud Logs

Rules detecting the same action

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

Account Security Configuration Changed (Panther)
AWS VPC Flow Logs Deleted (Sigma)
AWSCloudTrail - Changes made to AWS CloudTrail logs (Kusto)
AWSCloudTrail - Config Service Resource Deletion Attempts (Kusto)
AWSCloudTrail - Tampering to AWS CloudTrail logs (Kusto)

Rule body yaml

AnalysisType: rule
Filename: aws_vpc_flow_logs_deleted.py
RuleID: "AWS.VPCFlow.LogsDeleted"
DisplayName: "AWS VPC Flow Logs Removed"
Enabled: true
LogTypes:
  - AWS.CloudTrail
Severity: Info
Reports:
  MITRE ATT&CK:
    - TA0005:T1562.008 # Defense Evasion: Disable or Modify Cloud Logs

  Stratus Red Team:
    - aws.defense-evasion.vpc-remove-flow-logs
Description: "Detects when logs for a VPC have been removed."
Reference: 
  https://stratus-red-team.cloud/attack-techniques/AWS/aws.defense-evasion.vpc-remove-flow-logs/
Runbook: Look for an accompanying 'DeleteVpc' event, and confirm that they are related. if there is no matching VPC Deletion event, followup with the log removal to determine if it is legitimate.
Tags:
  - AWS
  - Cloudtrail
  - Defense Evasion
  - Impair Defenses
  - Disable or Modify Cloud Logs
  - Defense Evasion:Impair Defenses
  - Security Control
Status: Experimental
Tests:
  - Name: Logs Deleted
    ExpectedResult: true
    Log:
      {
        "p_event_time": "2024-11-26 19:29:38.000000000",
        "p_log_type": "AWS.CloudTrail",
        "p_parse_time": "2024-11-26 19:35:54.358700257",
        "awsRegion": "us-west-2",
        "eventCategory": "Management",
        "eventID": "d5e6d49c-0be9-4c53-ab8a-c7ca86edd130",
        "eventName": "DeleteFlowLogs",
        "eventSource": "ec2.amazonaws.com",
        "eventTime": "2024-11-26 19:29:38.000000000",
        "eventType": "AwsApiCall",
        "eventVersion": "1.10",
        "managementEvent": true,
        "readOnly": false,
        "recipientAccountId": "111122223333",
        "requestID": "1dcd7d36-72be-4aad-9e9d-93b88e0135ea",
        "requestParameters": {
          "DeleteFlowLogsRequest": {
            "FlowLogId": {
              "content": "fl-0ef673ef70c4f07cc",
              "tag": 1
            }
          }
        },
        "responseElements": {
          "DeleteFlowLogsResponse": {
            "requestId": "1dcd7d36-72be-4aad-9e9d-93b88e0135ea",
            "unsuccessful": "",
            "xmlns": "http://ec2.amazonaws.com/doc/2016-11-15/"
          }
        },
        "sourceIPAddress": "1.2.3.4",
        "tlsDetails": {
          "cipherSuite": "TLS_AES_128_GCM_SHA256",
          "clientProvidedHostHeader": "ec2.us-west-2.amazonaws.com",
          "tlsVersion": "TLSv1.3"
        },
        "userAgent": "sample-user-agent",
        "userIdentity": {
          "accessKeyId": "SAMPLE_ACCESS_KEY",
          "accountId": "111122223333",
          "arn": "arn:aws:sts::111122223333:assumed-role/SampleRole/leroy.jenkins",
          "principalId": "SAMPLE_PRINCIPAL_ID:leroy.jenkins",
          "sessionContext": {
            "attributes": {
              "creationDate": "2024-11-26T17:05:50Z",
              "mfaAuthenticated": "false"
            },
            "sessionIssuer": {
              "accountId": "111122223333",
              "arn": "arn:aws:iam::111122223333:role/aws-reserved/sso.amazonaws.com/us-west-2/SampleRole",
              "principalId": "SAMPLE_PRINCIPAL_ID",
              "type": "Role",
              "userName": "SampleRole"
            }
          },
          "type": "AssumedRole"
        }
      }

Detection logic

Condition

not (errorCode is_not_null or errorMessage is_not_null)
eventName eq "DeleteFlowLogs"

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`errorCode`	is_not_null	(no value, null check)
`errorMessage`	is_not_null	(no value, null check)

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	`DeleteFlowLogs`

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`
`accountId`	`userIdentity.accountId`

`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)