CT4.TOOLS
Best-of-breed open-source security products and tools. A curated reference library — anchored in Cybersecurity Transformation Chapter 10 — organized by the CT4-DEFENSE™ six-layer model. No vendor sponsorship. No paid placements.
"Tools do not create security. They amplify what already exists. A disciplined team with four well-chosen tools will outperform a reactive organization with seventeen every time. The art is not in acquiring tools — it is in knowing which layer of your defense each one serves, and whether your team can genuinely operate it."
— Cybersecurity Transformation, Chapter 10
Table 10.1 — The Core Open-Source Tool Stack
Nine tools, one per category, organized by CT4-DEFENSE™ layer. Each is open source, production-deployed at global scale, and selected after 15 years of SMB field work. For commercial alternatives in any category, Gartner Magic Quadrant and Forrester Wave are the appropriate starting points.
Wazuh (FIM module)
Monitors critical files for unauthorized changes using SHA-256 hashing. Immediate alert on any modification to records, configurations, or executables.
VeraCrypt
Encrypts drives, volumes, and containers using AES-256. Data at rest is unreadable without the key — even if the physical drive is removed.
OPNsense
Stateful packet inspection at the network edge. Blocks unsolicited inbound traffic. Encrypted site-to-site VPN between multiple locations.
Greenbone OpenVAS
Monthly credentialed scans identify known weaknesses across all systems. Generates prioritized remediation reports before attackers find the gaps.
Wazuh (EDR module)
Lightweight agent on every endpoint detects malware, suspicious process execution, and configuration gaps against CIS Benchmarks in real time.
Suricata
Monitors network traffic for attack signatures and anomalous patterns. Sits inline on the core switch at advanced program stages.
Keycloak
Single sign-on across all applications. MFA enforced from one console. Immediate access revocation when staff leave — the identity lifecycle, fully managed.
Wazuh (SIEM module)
Aggregates security logs from across the environment. Correlates events to detect patterns — five failed logins followed by a success, for example — and alerts.
Restic
AES-256 encrypted, deduplicated backups to offsite cloud storage. Nightly snapshots. Weekly verified restoration tests. The practical defense against ransomware.
Wazuh — One Platform · Three Layers
Wazuh appears three times in the shortlist — across three CT4-DEFENSE™ layers. That is not redundancy. One Wazuh deployment delivers coverage that would otherwise require three separate commercial platforms: one learning curve, one management console, one integration to maintain. Documentation: documentation.wazuh.com — among the best in any open-source security project.
The Three-Question Test
Before signing any contract — open-source or commercial — apply this test. All three questions must have specific, named answers. Not aspirations.
Which Layer?
Which CT4-DEFENSE™ layer does this tool serve? Every tool must map to a specific layer. A tool that cannot answer this question has no defined place in your architecture — and a tool without a layer is a tool without a purpose.
Which Process?
What process will this tool support? Not what the vendor promises — which specific, named process in your security program will this tool enable or improve? If you cannot name it, you are not ready to buy.
Who Operates It?
The named individual who owns deployment, configuration, tuning, and ongoing operation. Not the team — a specific person. If you cannot name them, you are not ready to buy.
Verify Before You Buy
🛡️ MITRE ATT&CK Evaluations
Hands-on testing of security products against real adversary techniques from the ATT&CK framework. No marketing claims — actual detection rates, tested independently. Free at attackevals.mitre.org. Use it before every major endpoint or SIEM evaluation.
📊 AV-Comparatives
Ongoing independent endpoint protection evaluations including Advanced Threat Protection tests. Results publicly available, regularly updated, and free.
📈 AV-TEST
Continuous independent testing of endpoint and corporate security products. Provides head-to-head comparisons of detection rates across major commercial endpoint platforms.
Continuous Tool-Stack Updates
CT4.TOOLS expands continuously beyond the inaugural Chapter 10 shortlist. New categories, new evaluations, new tool comparisons. Subscribe to be notified when the next batch publishes.