Best Practices for Safely Running Foundstone CredDigger in Your LabFoundstone CredDigger is a legacy credential discovery and password auditing tool that can help security teams locate weak or reused credentials across systems. Because CredDigger interacts with authentication mechanisms and may trigger alerts or accidentally impact systems, running it safely in a lab requires careful planning, controls, and documentation. This article covers best practices for preparing, configuring, executing, and reviewing CredDigger tests in an isolated environment while minimizing risk and staying within legal and ethical bounds.
1. Understand the tool and its risks
Before running CredDigger, learn what it does and how it behaves:
- CredDigger probes authentication services and attempts logins using supplied lists; it may generate many authentication attempts.
- It can trigger account lockouts, intrusion detection alerts, and logging that could be mistaken for real attacks.
- It may expose or store sensitive credential data if not handled securely.
Action items: review official tool documentation, change-logs, and community write-ups; run a small proof-of-concept on a single controlled target first.
2. Build a properly isolated lab environment
Never run credential-discovery tools against production systems. Create a lab that mirrors relevant services but is fully isolated from production and the internet:
- Use VLANs, separate physical hosts, or nested virtualization to segregate lab traffic.
- Ensure DNS, AD, mail, and other services you want to test are present but contain only test accounts and data.
- If possible, run the lab offline or with tightly restricted outbound access to reduce accidental exposure.
Example minimal lab components:
- Domain Controller (test AD) with a few OU structures and test user accounts.
- File servers, web servers, and other service endpoints configured with representative authentication settings.
- Monitoring/logging server to capture CredDigger activity.
3. Create dedicated test accounts and datasets
Use synthetic, non-production credentials and realistic password patterns:
- Create test user accounts with varying password strengths and lockout policies to observe tool behavior.
- Seed accounts with representative weak and strong passwords (e.g., “Password123!”, “S3rv!c3Acc0unt$”, randomized strong passphrases).
- Avoid using real user names or password fragments from production.
Document every account and credential used in tests in a secure, access-controlled location.
4. Configure account lockout and rate-limiting intentionally
To study realistic outcomes while preventing nuisance effects:
- Set lockout thresholds and observation windows to values that let you study lockouts without permanently disabling accounts.
- Implement rate-limiting and throttle CredDigger to simulate realistic attacker speeds while protecting lab services from overload.
Test example: set account lockout threshold to 10 invalid attempts with a 30-minute reset window; run CredDigger at a pace of 1–2 attempts per second and observe.
5. Run tests with least privilege and controlled networks
- Execute CredDigger from a dedicated jump host or VM with no additional network privileges.
- Disable any automatic credential forwarding or single-sign-on on the test host.
- Ensure the test host has limited access to other lab resources and no route to production networks.
6. Logging, monitoring, and alerts
Set up comprehensive logging to capture both the tool’s activity and the target systems’ responses:
- Enable detailed authentication logging on services (e.g., Windows Security log, SSH logs).
- Use an IDS/IPS and SIEM in the lab to observe how real monitoring reacts to the activity.
- Correlate CredDigger output with system logs to validate findings.
Store logs in a write-once or access-controlled repository to preserve evidence and support repeatability.
7. Secure handling of discovered credentials
CredDigger may reveal cleartext or partially hashed credentials. Treat them as sensitive:
- Store any discovered credentials in an encrypted password manager or vault, not in plain text files.
- Limit access to the vault to authorized testers only.
- After testing, rotate or retire any real-account equivalents if test data overlapped with production.
8. Use non-destructive configurations where possible
Prefer passive or read-only modes if the tool supports them:
- Where CredDigger offers auditing-only or discovery modes that avoid active brute-force attempts, use those first.
- Combine passive discovery with targeted active tests only when necessary and after review.
9. Maintain repeatability and documentation
Document each test run, configuration, wordlists, timer settings, and observed outcomes:
- Keep a changelog of lab configuration changes, CredDigger versions, and rule sets used.
- Version-control scripts and wordlists (in a private repo) to ensure reproducibility.
10. Legal, ethical, and organizational approvals
Even in a lab, follow internal policy:
- Obtain written authorization from system owners or a designated security lead.
- Ensure tests comply with organizational policies and, where relevant, legal/regulatory requirements.
- If third-party or vendor systems are involved, obtain their permission.
11. Post-test cleanup and hardening
After testing:
- Remove or reset test accounts and passwords.
- Review logs and remediation actions; document any weaknesses found.
- Harden lab systems based on findings (stronger passwords, adjusted lockout policies, MFA).
- Securely delete any temporary files that contain credentials or logs stored on ephemeral hosts.
12. Consider safer alternatives and complementary tools
Credential discovery can be done with lower risk using:
- Passive log analysis (audit logs, authentication telemetry).
- Password policy reviews and AD health checks.
- Modern vetted password auditing frameworks that support throttling and built-in safety checks.
Compare these options to CredDigger depending on your objectives.
Example safe run checklist (short)
- Lab isolated from production and internet: Yes/No
- Test accounts created and documented: Yes/No
- Lockout and rate-limits configured: Yes/No
- Monitoring enabled (SIEM/IDS/logging): Yes/No
- Secure storage for discovered credentials: Yes/No
- Written authorization obtained: Yes/No
CredDigger can provide useful insights into credential hygiene when used carefully. The keys to safe operation are isolation, documented test data, controlled execution rates, strong logging, and strict handling of any discovered secrets. Follow the steps above to reduce risk and produce defensible, repeatable results.
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