The people who handle breaches all day may be the worst at protecting themselves. Feeling invulnerable is what lets us function around constant threat, the way it lets doctors work around disease. Warnings about our own risk rarely stick. https://zeltser.com/illusion-of-invulnerability

A decoy fires only when someone accesses a resource no legitimate user would touch. Plant tripwires across network, identity, data, and AI agent configs to create asymmetry in your security architecture. https://zeltser.com/protean-information-security-architecture

One word changed a hospital hand-washing sign from 'protects you' to 'protects patients,' and compliance climbed. We discount our own risk but not other people's. The same holds for security messaging aimed at others, not ourselves. https://zeltser.com/illusion-of-invulnerability

An attacker on a developer's machine often pivots to reconnaissance. AI agent MCP configs are plain-text files at known paths, offering an index of high-value services. A decoy entry pointing to a honeypot MCP server alerts you of an intrusion. https://zeltser.com/decoy-mcp-server-honeypot

One should print out those rules, laminate them and give it to everyone in cyber.

When an executive rejects a security recommendation, it's worth asking what would need to change for a different answer. That question reveals constraints we didn't see and persuasion paths we didn't consider. https://zeltser.com/rejected-security-recommendations

"Fileless malware" started as Code Red's pure in-memory worm in 2001 and has evolved to cover other forms of evasion, including living-off-the-land. I traced the journey of the term through its 25-year history. https://zeltser.com/fileless-malware-beyond-buzzword

Much of our security work is communicating with colleagues throughout the org. 10 habits that sharpen how the technical work gets heard. https://zeltser.com/strong-communication-skills

Four tips for a strong executive summary of your security report. They apply whether you write it from scratch or draft it with AI's help: https://zeltser.com/executive-summary-for-security-assessment-report-tips

Existing AI security frameworks each cover one slice of the work, like components, risks, and lifecycle. The AI Defense Matrix combines them into a single grid of AI asset classes mapped to NIST CSF functions. https://zeltser.com/ai-defense-matrix-intro

A honeytoken fires when someone reaches for what they shouldn't, which makes the alerts high-signal. To get the most of them, decide on the best locations, such as decoy MCP entries, fake AWS keys, and Cloudflare Workers serving fake admin pages. https://zeltser.com/plant-honeytokens

If AI driven attacks become more prevalent, it'll only be a matter of time before attackers push the token burden on to their victims, using the AI that's already (probably) there. I'm calling it "living off the lAInd".* *Jokey name. Probably will happen, though.

A decoy in your AI agent's MCP config can be an early sign of an intrusion. Interactions with the honeypot MCP server mentioned there can be a high-confidence signal. Building this honeypot is pretty straightforward. https://zeltser.com/decoy-mcp-server-honeypot

Sounil Yu and I co-authored the AI Defense Matrix, the security-for-AI companion to his Cyber Defense Matrix. It maps eight AI asset classes to NIST CSF functions, so security leaders can find gaps and vendors map products. https://zeltser.com/ai-defense-matrix-intro

What exactly is "malware"? Here's my definition, so we don't need to rely on "We know it when we see it." https://zeltser.com/what-is-malware

Unnecessary complexity makes products hard to maintain and hard to secure. Modern apps such as Cloudflare's EmDash and Tailscale show that designing for simplicity produces stronger security as a side effect. https://zeltser.com/modern-design-security

Honeytokens are a time-tested idea, but the interesting part is where you plant them. Consider using them as decoy MCP entries, fake AWS keys, and Cloudflare Workers serving fake admin pages to detect intrusions. https://zeltser.com/plant-honeytokens

How do builders of security products assess strategies against vibe-coded competition? You can now use your AI agent and my MCP server, which carries Ben Vierck's seven-dimension defensibility rubric, included with his permission. https://zeltser.com/security-product-strategy-with-ai

SaaS vendors should assess whether their trust boundary includes customers' AI agents. Liability has pushed banks toward securing the customer's device four times, and the fifth wave is forming around AI agents. https://zeltser.com/saas-ai-agent-trust-boundary

Modern architectures make products easier to run, with security as a wonderful added benefit. Cloudflare's EmDash reimagines WordPress with no customer-managed server, and Tailscale connects devices with no VPN servers. Simpler designs leave less to attack. https://zeltser.com/modern-design-security

When evaluating a security vendor's strategy, your own product roadmap, or an investment target, AI can separate marketing claims from verified capabilities. But it needs the right domain-specific criteria. Here's how: https://zeltser.com/security-product-strategy-with-ai

Generic AI does generic work. Once Claude Code knows your tools, your conventions, and your past projects, its outcomes start fitting how you actually operate. The seven-layer Personal AI Stack lays out what to add and why. https://zeltser.com/personal-ai-stack

AIUC-1 is a purpose-built compliance framework for AI agent risks such as prompt injection that existing certifications don't cover. Scope, auditor dynamics, and incentive alignment will shape what its certificates are worth. https://zeltser.com/aiuc-1-cert

Out-of-the-box Claude Code is solid for general work. What makes it indispensable is the personalization, hardening, and connectors you layer on top. I mapped my setup into a seven-layer Personal AI Stack, so you can optimize yours.

SaaS vendors that make their products usable by customers' AI agents inherit those agents' attack surface. Liability and regulation drove banks into that position four times already. The same pressure is building for agent-era vendors now. https://zeltser.com/saas-ai-agent-trust-boundary

"The current generation of frontier models behaves like a gifted PhD student with imposter syndrome: brilliant when calm, and when the room turns against them, they over-apologize, hedge everything, and abandon positions they should defend." -- Dheer Gupta https://dheer.co/llm-anxiety/

Dan Nguyen-Huu walks through the economics of agentic procurement, a scenario where AI agents decide whether to build a capability from scratch or buy it from a vendor. https://dannguyenhuu.substack.com/p/the-token-threshold

You can now receive my blog posts via email. Go ahead and sign up: https://zeltser.com/newsletter I've been writing more frequently than I have in recent years, and I'd rather share my articles directly than rely on an algorithm to decide whether to surface them.

A thoughtful piece by Anthropic on AI-accelerated offense. In my mind, the only sustainable answer to vulnerability management is modern design and shrinking the attack surface. https://claude.com/blog/preparing-your-security-program-for-ai-accelerated-offense

We told employees to "be suspicious" of links they needed for work. Now we're adding "be careful with AI" to the awareness curriculum. Teaching when to escalate works better than teaching what to fear. https://zeltser.com/ai-influence-awareness-training

When an AI tool recommends an action and an employee carries it out, audit logs capture a legitimate human decision. The AI's role disappears. Addressing that blind spot takes more than awareness training. https://zeltser.com/ai-influence-awareness-training

We invest hours analyzing a security risk, and that effort makes us overvalue the recommendation. An executive who hasn't shared that analysis weighs the same risk differently, and they might be right. https://zeltser.com/rejected-security-recommendations

Are we winning the fight against cyber attackers? It's the wrong question. Framing the attacker-defender dynamic as a war fuels hype and leads to the wrong investments.

We scope security assessments along organizational lines, but attackers don't stop where one team's budget ends. Following attack logic instead of org charts closes the gaps.

Love them or hate them, SOC 2 reports have become table stakes for SaaS deals. But the framework leaves the vendor in control of the system boundary and auditor selection, which means the reports vary drastically in rigor.

Is a security product company building a true platform or a suite? The distinction clarifies where to invest, how to measure progress, and what competitive advantage to pursue. Here's my guidance for deciding which approach is best, including a look at CrowdStrike, Okta, and Palo Alto Networks.

Who'll win this year's RSAC Innovation Sandbox? I used my custom AI framework to score each finalist's market readiness across 8 dimensions and built detailed profiles. 4 companies clustered clearly ahead. See if you agree:

My guide for endpoint security startups is out now. The path between competing against entrenched platforms and becoming a feature they bundle is narrow. I got to know this space at Minerva Labs (now part of Rapid7), but much has changed since then.

My new guide on building security products for SMBs. The go-to-market has shifted heavily toward MSPs and VARs, channel concentration creates real dependency risk, and AI readiness among MSPs is lower than the hype suggests.

I published a 4-point approach for succeeding as a CISO, based on my experiences building and leading a security program at a high-growth company. It shows how to focus on the defender's advantage and escape the unending cycle of reacting to vulnerabilities and responding to attackers' advances:

Good tech alone doesn't make a successful security product. I created a guide covering the strategic questions founders and product managers should answer early, drawing on my experience as both a CISO and a product manager.

Security leaders are often trapped in endless assessments and opinion-giving without driving actual change. Staying busy with spreadsheets, dashboards, and emails doesn't move the organization forward. Here's how we can break out of the "Chief Opinion Officer" mode:

REMnux v8 brings AI integration to the Linux malware analysis toolkit 📖 Read more: www.helpnetsecurity.com/2026/02/17/r... #cybersecurity #cybersecuritynews #Linux #malwareanalysis #opensource @lennyzeltser.com

Which malware analysis toolkits and frameworks should you consider including in your workflow? Here's my overview:

The new REMnux MCP server connects AI agents to 200+ malware analysis tools on REMnux. I was surprised at the depth of investigation it delivers. Most of my time went into capturing how I approach the analysis and providing guidance to AI at the right time, so it can think and adapt as it works.

What if the CISO's real job is calibrating the right amount of insecurity? Frame the role around that and you become an enabler, not an obstacle. The acronym still works.

I released a free tool to generate animated, annotated replays of text conversations, so you can embed them in articles, training, and docs. For example, it's a nice way to explain influence tactics of a social engineering scam. See it in action:

How to give AI raw incident notes and get a solid draft of an IR report? Now you can point your AI tool at my MCP server for guidance based on proven writing principles. Your data isn't shared with my server; it only provides guidance.

I released a tool for making your website or docs easily available to AI assistants via an MCP server. This helps ensure people's AI tooling can access the latest details at the right time. For instance, this is how REMnux users now can get info about its malware analysis tools.

While cybersecurity and data privacy leaders have distinct expertise, their goals are aligned. Edy Glozman and I discussed how these functions can support each other based on our collaboration at Axonius: zeltser.com/security-pri...