CISA Case Study: Detection and Remediation of Exposed AWS GovCloud Keys

The Cybersecurity and Infrastructure Security Agency (CISA) recently disclosed details of an incident response engagement stemming from the exposure of sensitive AWS GovCloud credentials and internal data on a public GitHub repository. While the specifics of the breach are alarming, the mechanics are unfortunately common: accidental leakage of valid credentials into a version control system.

In 2026, with the rise of automated repository scraping and CI/CD dependency attacks, the window between a "git push" and credential compromise is often measured in minutes. For organizations operating in sensitive environments like AWS GovCloud, a single leaked access key can bypass expensive perimeter defenses, granting attackers direct access to regulated data. This breakdown outlines the technical anatomy of such leaks and provides the detection rules and remediation scripts necessary to lock down your environment.

Technical Analysis

Affected Platforms & Services:

• AWS GovCloud (US-East/West): Isolated AWS regions designed for U.S. government data and compliant workloads.
• Public GitHub Repositories: The source of the data leakage.

The Attack Vector:

1. Insider Error: A developer or engineer inadvertently commits a file containing AWS Access Keys (Access Key ID and Secret Access Key) or a configuration file (e.g., .env, terraform.tfvars) to a public repository.
2. Automated Discovery: Threat actors utilize automated tools that continuously monitor public Git commits for regex patterns matching AWS keys (AKIA[0-9A-Z]{16}).
3. Initial Access: Once a key is identified, attackers validate it against the AWS API. If active, they gain the privileges associated with that IAM user (often over-provisioned developer roles).
4. Privilege Escalation/Lateral Movement: In this scenario, the keys provided sufficient access to enumerate resources and potentially access sensitive data.

Exploitation Status: This method is a "living landscape" threat. While not a software vulnerability (CVE), it is a procedural vulnerability with a 100% exploitation rate once credentials are public. CISA has confirmed active use of these credentials in this incident, requiring immediate key revocation.

Detection & Response

SIGMA Rules

The following rules detect the behavioral indicators of a compromise: reconnaissance activities in CloudTrail (post-exploitation) and the potential源头 action of pushing secrets to Git.

---
title: AWS CloudTrail - Discovery/Enumeration Activity via Sensitive API Calls
id: 8a4b1c92-3f5d-4e6a-9b1c-8d4e5f6a7b8c
status: experimental
description: Detects potential discovery activities in AWS CloudTrail often performed immediately after credential compromise. Specifically targeting enumeration of users, roles, and buckets.
references:
  - https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-logged-events.html
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.discovery
  - attack.t1580
logsource:
  product: aws
  service: cloudtrail
detection:
  selection:
    eventSource:
      - 'iam.amazonaws.com'
      - 's3.amazonaws.com'
    eventName:
      - 'ListUsers'
      - 'ListRoles'
      - 'GetUser'
      - 'ListBuckets'
      - 'GetAccountAuthorizationDetails'
  filter_known_admin:
    userIdentity.type: 'IAMUser'
    userIdentity.userName|contains:
      - 'admin'
      - 'svc-account'  # Adjust based on known service accounts
  condition: selection and not filter_known_admin
falsepositives:
  - Legitimate administrative auditing
level: medium
---
title: Git - Potential Secret Push to Public Repository
id: 9c5d2e83-4g6h-5i7j-0k1l-2m3n4o5p6q7r
status: experimental
description: Detects git push commands to public destinations (e.g., github.com, gitlab.com) which could accidentally expose secrets.
references:
  - https://attack.mitre.org/techniques/T1560/001/
author: Security Arsenal
date: 2026/04/06
tags:
  - attack.exfiltration
  - attack.t1567.001
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith:
      - '\git.exe'
      - '\git.cmd'
    CommandLine|contains:
      - 'push origin'
    CommandLine|contains:
      - 'github.com'
      - 'gitlab.com'
      - 'bitbucket.org'
  condition: selection
falsepositives:
  - Developers pushing legitimate code to public OSS repositories
level: low

KQL (Microsoft Sentinel)

This query hunts for successful AWS API calls originating from locations or user agents inconsistent with your organization's standard baseline, a hallmark of external actors using stolen keys.

AWSCloudTrail
| where EventName in ('ConsoleLogin', 'AssumeRole', 'GetUser')
| where IsError == false
| extend SourceIP = SourceIpAddress
| join kind=leftouter (GeoNetwork | project SrcIP, Country) on $left.SourceIP == $right.SrcIP
| project TimeGenerated, EventName, SourceIpAddress, Country, UserIdentityArn, UserAgent
| where Country !in ('United States', 'Your_Country_Code') // Adjust to your specific region
| where UserAgent !contains "aws-cli" and UserAgent !contains "console.aws.amazon.com"
| sort by TimeGenerated desc

Velociraptor VQL

This artifact hunts endpoint file systems for common file types known to house hard-coded credentials, allowing you to find the leak before it is pushed or remediate systems where developers accidentally stored keys.

-- Hunt for common credential storage files on endpoints
SELECT FullPath, Size, Mtime
FROM glob(globs=[
  '/home/*/.aws/credentials',
  '/Users/*/.aws/credentials',
  'C:/Users/*/.aws/credentials',
  '/tmp/*.env',
  'C:/Temp/*.env',
  '**/terraform.tfvars',
  '**/secrets.yaml'
])
WHERE Mtime > ago(-7d) -- Focus on recently modified files

Remediation Script (PowerShell)

This script scans local directories for strings matching the AWS Access Key pattern (AKIA...) to identify potential leakage points on developer workstations.

# Scan for AWS Access Key ID patterns in common project directories
$Pattern = 'AKIA[0-9A-Z]{16}'
$PathsToScan = @("C:\Users\$env:USERNAME\Source", "C:\Projects", "C:\Repos")

Write-Host "Starting scan for AWS Access Key IDs..."

foreach ($Path in $PathsToScan) {
    if (Test-Path $Path) {
        Write-Host "Scanning path: $Path"
        Get-ChildItem -Path $Path -Recurse -Include *.txt, *.py, *.js, *.tf, *.env, *., *.xml, *.cs -ErrorAction SilentlyContinue | 
        Select-String -Pattern $Pattern | 
        ForEach-Object {
            Write-Host "[!] POTENTIAL CREDENTIAL FOUND in: $($_.Path)"
            Write-Host "    Line: $($_.Line.Trim())"
        }
    }
}
Write-Host "Scan complete."

Remediation

Based on CISA's incident response findings, organizations must take the following immediate actions:

1. Immediate Credential Revocation: If a credential is suspected to be leaked, treat it as compromised. Immediately deactivate the corresponding Access Keys in the IAM console and delete them.
2. Credential Rotation: Generate new keys for the required IAM users, ensuring they are stored securely (e.g., AWS Secrets Manager) rather than in code.
3. Audit IAM Permissions: Ensure that the compromised keys did not have over-privileged access. Implement the principle of least privilege.
4. Implement Pre-Commit Hooks: Mandatory installation of tools like TruffleHog or Git-Secrets in developer environments to scan commits for regex patterns of keys before they are pushed to the repository.
5. Enable Secret Scanning: Enable GitHub Secret Scanning or equivalent Git provider features to automatically detect and notify of committed secrets.
6. Review CloudTrail Logs: Conduct a forensic review of CloudTrail logs for the duration the key was active to identify any unauthorized resources created or data accessed.

Related Resources

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