CIS AWS Foundations v1.2 3.3: A log metric filter and alarm should exist for usage of the "root" user

To meet the cis aws foundations v1.2 3.3: a log metric filter and alarm should exist for usage of the "root" user requirement, you must (1) ensure AWS CloudTrail logs are sent to CloudWatch Logs, (2) create a CloudWatch Logs metric filter that detects Root user activity, and (3) attach an alarm that notifies your incident channel immediately. ¹

Key takeaways:

• Detect root activity via a CloudWatch Logs metric filter over CloudTrail events, then alarm on matches. ¹
• Scope this per AWS account and per region where CloudTrail events are generated and monitored. ²
• Keep evidence that the filter pattern, metric, alarm actions, and notification path are working, not just configured. ³

Root is the highest-privilege identity in an AWS account, and you usually want it unused except for rare break-glass situations. CIS AWS Foundations v1.2 control 3.3 is a detection-and-response requirement: you are expected to have automated monitoring that identifies Root usage and generates an alert so your team can investigate immediately. ¹

Operationally, auditors and internal assurance teams look for two things: (1) a technically correct signal that triggers on Root activity captured by CloudTrail, and (2) a reliable notification path to people and systems that can respond. If your organization runs a multi-account AWS environment, this also becomes a consistency problem: you need a repeatable way to deploy the same detection everywhere, and a way to prove it stays in place after account vending, region expansion, and team changes. ¹

This page gives you requirement-level implementation guidance: plain-English interpretation, applicability, step-by-step build steps, evidence to retain, audit questions, common mistakes, and a practical execution plan.

Requirement: CIS AWS Foundations v1.2 3.3 (Root user usage alarm)

Objective: Generate an alert whenever the AWS account Root user is used (console login, API calls, or other Root-attributed activity) by detecting the event in CloudTrail logs and alarming via CloudWatch. ¹

Plain-English interpretation

You need an automated “tripwire” for Root. If Root is used, your monitoring should create a measurable event (metric) and raise an alarm that notifies your response workflow. This is not satisfied by “we restrict Root” or “we have MFA on Root” alone; the control is specifically about detection + alerting tied to log evidence. ¹

Who it applies to

Entity types: AWS cloud operators and any organization responsible for configuring AWS account security baselines. ¹

Operational context where it matters most:

• Multi-account organizations (AWS Organizations) where Root exists per account and centralized governance is required.
• Regulated environments where privileged access must be monitored and incident response must be provable.
• Any account used for production workloads, sensitive data, or security tooling, because Root use is a high-risk signal even when legitimate. ³

Why auditors care (risk implications)

Root can bypass many normal controls. If an attacker gains Root access, they can disable logging, change security settings, and persist access. A Root-use alarm gives you a narrow but critical early warning. From a governance view, it also enforces the expectation that Root is “break glass,” not daily operations. ³

Regulatory text

“Implement CIS AWS Foundations Benchmark v1.2 requirement 3.3 as mapped in AWS Security Hub.” ¹

What that means for an operator: implement the CIS 3.3 control in the way AWS Security Hub evaluates it: CloudWatch log metric filter(s) and alarm(s) that detect Root user usage from CloudTrail log events and generate notifications. Your implementation must be demonstrable with configuration evidence and operational proof (for example, test events and alarm history). ²

What you actually need to do (step-by-step)

Step 1: Confirm CloudTrail is logging management events to CloudWatch Logs

1. Verify CloudTrail is enabled and capturing management events for the account(s) in scope.
2. Verify the trail delivers to a CloudWatch Logs log group (not only S3), because the metric filter evaluates CloudWatch Logs.
3. Confirm you are collecting events from all relevant regions according to your CloudTrail strategy and your Security Hub CIS evaluation approach. ²

Operator note: Many environments have a centralized org trail. That’s fine, but the metric filter must be created on the log group that actually receives the events you want to evaluate. ²

Step 2: Create a CloudWatch Logs metric filter for Root usage

1. In CloudWatch Logs, select the CloudTrail log group.
2. Create a metric filter that matches Root activity in CloudTrail events. Your filter should be explicitly designed for Root identity, not generic “ConsoleLogin failures.”
3. Configure the filter to emit a custom metric (namespace + metric name) when a matching event is found.
4. Document the filter pattern and the specific log group(s) where it is deployed. ¹

Implementation decision point (write it down):

• Signal definition: What exact CloudTrail fields define “Root usage” for your organization’s detection? Keep this consistent across accounts so alerts mean the same thing everywhere. ³

Step 3: Create a CloudWatch alarm on the metric

1. Create an alarm that triggers when the Root usage metric is greater than your threshold.
2. Configure alarm actions to notify an SNS topic (or your alerting integration connected to SNS).
3. Ensure the SNS topic routes to your on-call / incident channel (email, ticketing, chatops, SIEM/SOAR).
4. Confirm the alarm is enabled and in “OK” state initially (not “Insufficient data” indefinitely due to missing log ingestion). ¹

Practical alerting guidance: Route Root alarms to a high-signal channel with clear ownership. If nobody is accountable for the alert, auditors will treat it as a design failure even if the configuration exists. ³

Step 4: Test the control (prove it works)

1. Conduct a controlled test in a non-production or designated account if possible.
2. Generate a Root event consistent with your defined “Root usage” signal (for example, a Root console login where permitted by your policy).
3. Verify: CloudTrail event appears → CloudWatch Logs receives it → metric increments → alarm transitions to ALARM → notification is delivered.
4. Capture screenshots or exported logs for the evidence package. ¹

Step 5: Operationalize across accounts (governance)

1. Standardize deployment using infrastructure-as-code or a baseline automation approach so every new account gets the filter + alarm.
2. Add continuous monitoring: AWS Security Hub can report whether the CIS mapping check remains passing. ²
3. Establish an exception process for accounts that cannot meet the check immediately (with compensating controls and a remediation date). ³

Where Daydream fits: Daydream is useful for mapping the CIS requirement to your internal controls, tracking which accounts are in-scope, and collecting recurring evidence (config + test proof) for audits without rebuilding the packet each cycle. ¹

Required evidence and artifacts to retain

Keep evidence in a single “CIS 3.3 Root usage alarm” packet per environment (or per AWS Organization), updated as changes occur.

Configuration evidence (design):

• CloudTrail configuration showing logs delivered to the relevant CloudWatch Logs group(s). ²
• CloudWatch Logs metric filter configuration: log group name, filter pattern, metric namespace/name. ³
• CloudWatch alarm configuration: threshold, evaluation period settings, SNS topic/action targets. ³

Operational evidence (effectiveness):

• Alarm history showing state transitions and timestamps.
• SNS delivery confirmation or downstream ticket/alert record.
• A test record: date, tester, method, expected outcome, actual outcome, and artifacts (screenshots/exports). ³

Governance evidence:

• Control narrative: “Root usage is monitored via CloudWatch metric filter and alarm; alerts route to X; responders follow Y runbook.” ³
• Runbook for investigating Root usage alerts (triage steps, containment actions, escalation). ³

Common exam/audit questions and hangups

Q1: “Show me the exact filter and alarm.”
Be ready to show the log group, metric filter pattern, metric, and alarm actions end-to-end. Auditors often fail teams that can only show an alarm but not the upstream filter. ²

Q2: “How do you know it works?”
A passing Security Hub posture result helps, but auditors still ask for test evidence or alarm history. Produce a controlled test record. ²

Q3: “Is this everywhere?”
If you have multiple AWS accounts or regions, expect sampling. Document your rollout method and provide an account inventory with deployment status. ³

Q4: “Who gets alerted, and what do they do?”
An alarm that emails a dead mailbox fails in practice. Provide an on-call alias, ticket queue, or SOAR workflow and show recent alert handling records if available. ³

Frequent implementation mistakes (and how to avoid them)

1. CloudTrail logs go only to S3, not CloudWatch Logs.
   Fix: ensure CloudTrail sends to CloudWatch Logs for the evaluated scope; the metric filter needs CloudWatch Logs ingestion. ²

2. Filter pattern matches the wrong identity type (misses Root API calls or only catches console login).
   Fix: define “Root usage” based on CloudTrail identity attributes and validate with test events that represent your threat model. ³

3. Alarm exists but no notification action is configured (or SNS topic has no subscribers).
   Fix: validate the full notification chain; store evidence of delivery. ³

4. Central log account receives CloudTrail, but the filter is deployed in a different account/log group.
   Fix: place metric filters where the CloudTrail events land; document centralization design. ²

5. No ownership or runbook, so alerts are ignored.
   Fix: assign responder group, define triage steps, and include it in incident management procedures. ³

Practical 30/60/90-day execution plan

Day 0–30: Stand up the detection in a pilot account

• Confirm CloudTrail-to-CloudWatch Logs ingestion for your pilot scope. ²
• Implement the metric filter and alarm, wire to SNS and your incident channel. ³
• Run a controlled test and archive the evidence packet. ³
• Draft the Root usage alert runbook (triage, containment, escalation). ³

Day 31–60: Roll out broadly and make it repeatable

• Deploy the same filter/alarm pattern across in-scope accounts using your standard change mechanism (IaC, baseline automation, or account vending templates). ³
• Turn on AWS Security Hub CIS reporting for visibility into drift and gaps. ²
• Define exceptions: what qualifies, who approves, and what compensating monitoring exists. ³

Day 61–90: Prove ongoing operation and close audit gaps

• Run a scheduled test (or tabletop) for Root alert handling and capture outcomes. ³
• Set up periodic evidence capture: alarm configuration exports, alarm history snapshots, and a record of notification routing. ³
• Prepare an audit-ready narrative that maps the requirement to the deployed controls and verification method, and keep it current as accounts change. ³

Frequently Asked Questions

Do I need this in every AWS account or only the management account?

CIS 3.3 is evaluated per account context because Root exists per account. Implement it everywhere you operate AWS accounts, or document why an account is out of scope and how you detect Root activity there. ³

Does Security Hub automatically create the metric filter and alarm for me?

Security Hub reports posture against the CIS mapping, but you still need to implement the underlying CloudWatch metric filter and alarm configuration. Treat Security Hub as validation and monitoring for drift. ²

We disable Root access keys. Do we still need this?

Yes. Root can still be used for console logins and certain account-level actions. The requirement is about alerting on Root usage events in logs, not only preventing access keys. ³

Can I send the alert to our SIEM instead of email?

Yes, as long as the CloudWatch alarm action results in timely notification and your team can demonstrate receipt and response. SNS-to-SIEM/SOAR or SNS-to-ticketing is common, but you must retain evidence of delivery. ³

What evidence is most persuasive in an audit?

The strongest packet shows configuration (trail → log group → metric filter → alarm → action) plus operational proof (a test event and alarm history with notification). This ties design to effectiveness. ¹

How do we handle break-glass Root usage without generating noise?

Keep the alarm, but pair it with a runbook that recognizes approved break-glass events. Require a change ticket or incident record for any Root use so each alert closes with documented justification. ³

Related compliance topics

• 03.01.18: Access Control for Mobile Devices
• 03.01.19: Withdrawn
• 03.01.20: Use of External Systems
• 03.01.21: Withdrawn
• 03.01.22: Publicly Accessible Content

Footnotes

1. CIS AWS Foundations Benchmark; AWS Security Hub CIS AWS Foundations mapping table

2. AWS Security Hub CIS AWS Foundations mapping table

3. CIS AWS Foundations Benchmark