Pacu

What is Pacu?

• Pacu is named after a type of Amazonian fish, symbolizing its role as a lightweight yet effective tool for navigating the AWS cloud environment.

• Developed by Rhino Security Labs, Pacu offers modular functionality, meaning users can load different modules to perform specific tasks such as privilege escalation, data exfiltration, or service enumeration.

---

Key Features of Pacu:

1. Modular Structure:

   • Pacu works through modules designed for individual tasks. You can run these modules independently, depending on your goals.

   • Examples:

     • IAM privilege escalation checks

     • Lambda service enumeration

     • S3 bucket enumeration

2. Credential Management:

   • Pacu allows testers to store and switch between AWS credentials to target multiple accounts. This is useful when evaluating security across different environments.

3. Simulated Exploits:

   • It can simulate privilege escalation, insecure S3 configurations, and token compromise scenarios.

   • The tool does not actively exploit vulnerabilities but shows how vulnerabilities can be abused.

4. Persistence and Attack Automation:

   • Supports creating persistent backdoors (e.g., rogue IAM users).

   • It automates common attack paths like escalating permissions or gaining unauthorized access.

5. Interactive Command-Line Interface (CLI):

   • Pacu operates from a Python-based interactive CLI where modules can be called, and results are saved in session-based projects for reporting and tracking.

6. Reporting and Session Persistence:

   • Sessions allow testers to save progress and generate reports on what vulnerabilities or issues were identified during the testing.

---

Common Modules in Pacu:

1. IAM-Related Modules:

   • iam__enum_users_roles_policies: Enumerates IAM users, roles, and attached policies.

   • iam__privesc_scan: Scans for privilege escalation opportunities (like policies with Action: *).

2. S3 Storage Modules:

   • s3__enum_buckets: Identifies public and private S3 buckets.

   • s3__bucket_takeover: Simulates bucket takeover scenarios.

3. Lambda and EC2 Modules:

   • lambda__enum: Lists AWS Lambda functions and their permissions.

   • ec2__enum: Enumerates EC2 instances, security groups, and networking configurations.

4. Credential Modules:

   • iam__backdoor_users_keys: Generates backdoor IAM users with programmatic keys.

   • iam__create_keys: Creates new access keys for existing IAM users (if allowed by permissions).

5. Networking Modules:

   • vpc__enum: Enumerates VPCs, subnets, and network ACLs.

   • route53__enum_zones: Lists DNS zones configured in AWS Route 53.

---

Example Workflow Using Pacu:

1. Setup and Configuration:

   • Clone the Pacu repository:

     bashCopy codegit clone https://github.com/RhinoSecurityLabs/pacu.git
     cd pacu
     pip install -r requirements.txt

   • Start Pacu:

     bashCopy codepython3 pacu.py

2. Load AWS Credentials:

   • Use the command to load AWS credentials:

     bashCopy codeset_keys

   • Switch between multiple credentials during the session using:

     bashCopy codeuse_profile

3. Run Modules:

   • Run an enumeration module (e.g., S3 buckets):

     bashCopy coderun s3__enum_buckets

   • Scan for privilege escalation opportunities:

     bashCopy coderun iam__privesc_scan

4. Review Findings:

   • List session results using:

     bashCopy codelist_sessions

   • Export results to a JSON or text report.

---

Use Cases for Pacu in AWS Security Testing:

1. Identify Misconfigurations:

   • Misconfigured IAM roles, public S3 buckets, over-permissioned Lambda functions.

2. Privilege Escalation Testing:

   • Assess IAM policies to see if attackers can escalate their privileges.

3. Simulate Insider Threats:

   • Test how compromised credentials or misconfigured services could be abused.

4. Evaluate S3 Security Posture:

   • Ensure no public buckets expose sensitive information.

5. Validate Security Controls:

   • Test persistence mechanisms like rogue IAM users and validate if security monitoring tools detect them.

---

Benefits of Pacu:

• Free and open-source: Anyone can use and customize it.

• Modular flexibility: Only load the modules you need for a specific test.

• Interactive CLI: Provides an easy-to-use interface for beginners and experts.

• Reporting features: Useful for compliance and documentation after testing.

---

Limitations of Pacu:

1. No Active Exploits: Pacu is designed to simulate attacks but won’t directly exploit AWS services.

2. AWS API Rate Limits: Since Pacu relies on AWS APIs, it may run into throttling limits during large-scale assessments.

3. Lacks Active Blue Team Evasion: Unlike other tools, Pacu doesn’t focus heavily on stealth (e.g., bypassing CloudTrail logging).