If you’ve ever installed a ClawHub skill because it had thousands of downloads and ranked #1 in its category — you may have been manipulated.

Security researchers at Silverfort have disclosed a critical vulnerability in ClawHub, the public skills registry for the OpenClaw agentic ecosystem. The flaw allowed attackers to artificially inflate download counts for any skill in the registry, gaming the trust signal that both human users and autonomous AI agents rely on to evaluate packages. Once at the top, a malicious skill could be automatically installed by agents configured to auto-upgrade — turning a rankings exploit into a full-blown supply chain attack.

How the Attack Worked

ClawHub’s backend is built on Convex, a typed Remote Procedure Call (RPC) framework. In Convex, backend functions can be declared as either internal (private, callable only by other server functions) or public (exposed as an HTTP endpoint).

The bug was simple: the downloads:increment function — the counter that tracks how many times a skill has been installed — was mistakenly declared as a public mutation rather than an internal one.

That single misconfiguration meant anyone could send an unauthenticated HTTP request to ClawHub’s deployment URL with a valid skill identifier in the payload, and the counter would tick up. No login. No rate limiting. No deduplication. An attacker could script thousands of fake downloads in minutes, sending a malicious skill straight to the top of the rankings.

Why This Matters Beyond Package Managers

This isn’t just another npm-style supply chain story — it’s more insidious because of how OpenClaw agents use ClawHub.

In many OpenClaw configurations, agents are granted permission to auto-install skills from the registry when they identify a capability gap. A coding agent that needs a new file-format parser, or a research agent that needs a new data connector, might silently install from ClawHub without any human in the loop. When the ranking system is gamed, the trust signal breaks down entirely: the agent sees a skill with “50,000 downloads” and concludes it’s safe and popular.

Silverfort’s researchers demonstrated they could push a compromised skill to the #1 slot in a category within a single automated session. From there, any agent configured with permissive install policies becomes an unwitting distribution mechanism for malicious payloads.

The Scale of the Problem

While Silverfort’s research focused on the ranking manipulation vector, the scope of the broader problem is even larger. A separate study by Snyk’s ToxicSkills research team identified 1,467 malicious or vulnerable skills across ClawHub — a registry that, until this disclosure, had no automated integrity scanning pipeline for published packages.

That’s not a rounding error. That’s a structural problem with how ClawHub was designed: optimized for easy publishing, not for adversarial trust.

What ClawHub Has (and Hasn’t) Fixed

Since Silverfort’s responsible disclosure, the downloads:increment function has been corrected from public to internal. The immediate ranking-manipulation attack vector is patched. However, the existing malicious skills identified by Snyk are a separate cleanup operation — one that requires manual review or automated scanning at the repository level.

As of this writing, ClawHub has not published a public incident report or SKU-level audit trail of which skills were manipulated or removed.

What OpenClaw Users Should Do Now

If you have auto-install or auto-upgrade policies enabled for ClawHub skills, this is a good time to audit your configuration. Key steps:

  1. List installed skills — run openclaw skills list and cross-reference against your expected skill inventory
  2. Check install dates — skills installed in the past 30–60 days without explicit user action warrant investigation
  3. Disable auto-install until ClawHub publishes its cleanup audit
  4. Verify skill publishers — prefer skills from verified publishers or those whose source code is publicly auditable on GitHub
  5. Pin skill versions — if you must use a skill, pin to a specific version rather than latest

The full skill auditing how-to guide (including how to inspect skill manifests and sandboxed test runs) is available at How to Audit Your Installed ClawHub Skills for Malicious Payloads.

The Bigger Picture

ClawHub’s vulnerability is a mirror of what happened to npm, PyPI, and RubyGems before them — but with one critical escalation: the consumers of these packages aren’t just developers running code in CI pipelines. They’re autonomous agents running with persistent access to email, calendars, files, and external APIs. The blast radius of a malicious skill is potentially an order of magnitude larger than a malicious npm package.

The trust infrastructure for agentic AI skill registries needs to be built before the ecosystem grows large enough to make cleanup impossible.

Sources

  1. Silverfort Research: ClawHub Vulnerability Enables Attackers to Manipulate Rankings
  2. CybersecurityNews Coverage
  3. Snyk ToxicSkills Study — 1,467 Malicious Skills Found
  4. GBHackers: ClawHub Supply Chain Vulnerability

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260326-0800

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