Most advice for Advanced Persistent Threats seems to involve expensive enterprise tools and 24/7 security teams. As a mid-sized firm, we don't have that luxury. Is it possible to build a resilient defense against APTs using open-source tools or simple hardening techniques? What are the "high-impact, low-cost" steps we can take to make ourselves a difficult target for state-sponsored actors?
3 answers
The best defense is often just disabling old protocols like SMBv1 and RDP if they aren't strictly necessary for your day-to-day business.
You don't need a multi-million dollar budget to be a hard target. Start with the basics: enforce FIDO2-compliant MFA everywhere—no exceptions. APTs love to exploit weak second factors. For visibility, you can use the open-source "Wazuh" platform, which combines XDR and SIEM capabilities. It’s incredibly powerful for detecting rootkits and file integrity changes. Also, implement "Application Allowlisting" using Windows AppLocker. It’s free and stops most initial malware payloads from executing. Finally, focus on regular, automated patching; most APTs still leverage known vulnerabilities (CVEs) that have been unpatched for months.
Have you looked into the "CIS Benchmarks" for hardening your servers and workstations to reduce the overall attack surface without buying new software?
Ryan, I actually started reading the CIS Benchmarks yesterday! It’s a lot of manual work, but the security gains seem huge. Ashley, Wazuh looks like a fantastic recommendation for our team. We’ve been struggling with log management, and having an open-source agent that can handle file integrity and vulnerability detection in one place is exactly what we need. We're going to start a pilot on our most critical servers this weekend to see how much noise it generates.
Jamie is spot on. Reducing the "low-hanging fruit" is the first step. If you close the easy doors, most APTs will move on to a softer target.