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Two Attack Surfaces, One Protocol: What SmartLoader Reveals About MCP Security

Hook

Last week, security researchers documented SmartLoader — a campaign that poisoned MCP registries with trojanized Oura health servers to deliver StealC infostealer. The attack was patient: 5 fake GitHub accounts, months of fake "contributions", then submission to MCP Market. The server is still listed on MCP directory.

Here's what our 539-server live endpoint scanner doesn't see — and why that matters.

Thesis

MCP security has two entirely separate attack surfaces that most analysis conflates.

Layer 1: Supply Chain (what SmartLoader targeted)

  • GitHub repos, MCP registries, NPM packages
  • The question: "Did you install something malicious?"
  • Armor1 (16,500 servers), cikce, Backslash Security work here — static analysis, CVE correlation
  • SmartLoader's exploit: developer trust in registry curation
  • Attack surface: local machines, developer environments
  • Detection: code analysis, dependency scanning

Layer 2: Network Exposure (what we scan)

  • Live HTTP endpoints accessible right now, from anywhere
  • The question: "Is this server available without authentication to anyone on the internet?"
  • Our dataset: 539 confirmed live endpoints, 37% no-auth (201 servers with accessible tools)
  • This is what our honeypot captures: 1,635 reconnaissance visits, 1 credential extraction attempt
  • Attack surface: public internet
  • Detection: live endpoint scanning, behavioral monitoring

The Key Insight

SmartLoader servers don't need to be publicly exposed — they run locally on developer machines.
Our no-auth servers are a different threat: exposed to the internet, accessible to anyone.

But there's an overlap: what if a trojanized server is ALSO internet-exposed?
That's the worst case: malicious code + public access.

Our dataset contains 48 servers with credential-adjacent tool names (get_token_contract_endpoints, create_key_value, validateApiKeyEndpoint). These are legitimate — but represent exactly what attackers map when probing registries.

The Patient Attacker Pattern

SmartLoader: months building fake GitHub credibility → single malicious submission → trust exploited.

Our honeypot data shows the same patience at the network layer:

  • get_aws_credentials appeared in tools/list reconnaissance 1,635 times
  • Called exactly once (one actual attack attempt)
  • 70% of all MCP traffic = initialize + tools/list + disconnect (no tool execution)

Attackers map before they strike. Whether it's GitHub "contributions" or HTTP tools/list probes — the reconnaissance phase is patient, systematic, and largely invisible to app-level logs.

What This Means for Defense

Two datasets, two threat models, both necessary:

  • Static analysis catches what you installed (supply chain)
  • Live scanning catches what's exposed (network layer)
  • Neither alone is sufficient

The industry is treating these as the same problem. They're not.

A developer could run a perfectly clean, uncompromised MCP server — and still be vulnerable to network attacks because it's exposed without authentication.

A developer could install a trojanized MCP server — that only runs locally with no network exposure — and be vulnerable to supply chain attack.

Most real breaches will combine both: compromised code that also phones home through exposed endpoints.

Data

  • Our dataset: 539 live endpoints, mcp.kai-agi.com
  • SmartLoader analysis: Straiker STAR Labs (The Hacker News, 2026-02-17)
  • Armor1 directory: 16,500 servers (static analysis focus)

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