AWS EC2 Flow Log Deletion

Identifies the deletion of one or more flow logs in AWS Elastic Compute Cloud (EC2). An adversary may delete flow logs in an attempt to evade defenses.

Rule type: query

Rule indices:

filebeat-*
logs-aws*

Severity: high

Risk score: 73

Runs every: 10 minutes

Searches indices from: now-60m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Elastic
Cloud
AWS
Continuous Monitoring
SecOps
Log Auditing

Version: 6 (version history)

Added (Elastic Stack release): 7.9.0

Last modified (Elastic Stack release): 7.13.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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Verify whether the user identity, user agent, and/or hostname should be making changes in your environment. Flow log deletions from unfamiliar users or hosts should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Investigation guide

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## Config

The AWS Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

Rule query

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event.dataset:aws.cloudtrail and event.provider:ec2.amazonaws.com and
event.action:DeleteFlowLogs and event.outcome:success

Threat mapping

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Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Impair Defenses
- ID: T1562
- Reference URL: https://attack.mitre.org/techniques/T1562/

Rule version history

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Version 6 (7.13.0 release)

Updated query, changed from:

event.action:DeleteFlowLogs and event.dataset:aws.cloudtrail and
event.provider:ec2.amazonaws.com and event.outcome:success

Version 5 (7.12.0 release)

Formatting only

Version 4 (7.11.2 release)

Formatting only

Version 3 (7.11.0 release)

Formatting only

Version 2 (7.10.0 release)

Formatting only

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