How I Would Have Stopped the March 2026 Axios Supply Chain Attack (Free Tool Inside)

On March 31, 2026, attackers published compromised versions of axios — npm's most downloaded HTTP client — containing a Remote Access Trojan hidden in a transitive dependency. The payload exfiltrated environment variables, SSH keys, and API credentials from every developer who ran npm install. I run an MCP server with API keys for 55 connected services. When I saw the advisory, I realized how exposed the entire AI tool ecosystem is to supply chain attacks. So I built 0nDefender. The Key Insight: Timing Most security tools scan AFTER packages are installed. The axios attack used a postinstall script — by the time your scanner runs, the malicious code has already executed. 0nDefender's core mechanism is a preinstall hook. It runs BEFORE npm resolves, downloads, or installs anything. { "scripts": { "preinstall": "npx 0nmcp@latest defender scan --lockfile" } } The hook reads package-lock.json, cross-references against known malicious versions, pattern-matches against typosquatter names, an