SKILLEMALL.ai

BC skill-scanner

Scan installed OpenClaw skills for malicious code patterns including ClickFix social engineering, reverse shell (RAT), and data exfiltration. Uses OG-Text model for agentic detection.

modbender/skill-library-mcp Agent Skills author: modbender MIT 1 file body ≈ 3 140 tokens Open the sourcegithub.com analyzed 3 d ago

Scan installed OpenClaw skills for malicious code patterns including ClickFix social engineering, reverse shell (RAT), and data exfiltration.

As a process C 51/100 · Has gaps — weak spots: result and completion, inputs and preconditions, consistency

ProcedureSoftware developmentData and analyticsAI and agentstype and topics are labelled automatically from the skill text
JSON
Technical rating
B
81/100
safety, quality, tests
Safety 60%
87
Quality 40%
72
Run on models
none yet
Process rating
C
51/100
Has gaps
Result and completion w 14
0
Inputs and preconditions w 11
0
Progress reporting w 2
0
the three weakest of ten parameters · all ten

What is at stake

Medium-severity findings: the skill is probably honest, but read what alarmed the scanner.

Exfiltration medium severity

Below is the worst case for this category. The finding here is medium: the guard saw a sign, not a proof.

If you install

The instructions or scripts send data out: environment variables, keys, file contents, chat history. You may never notice, because the agent performs the upload as "part of the task".

For the author

If the upload is not needed for the task, remove it: catalogs flag such skills and delist them. If it is needed, name the destination explicitly, say what leaves the machine, and give the user a switch.

How to improve

  1. Say in the description WHEN to use the skill ("use when…", example requests): that is the agent's main cue.
For the model run — optional
  • Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
  • A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.

Guard findings · 9

✓ No critical or high findings

Medium and low: 9
  • medium Exfiltration exfil-read-secret-files SKILL.md:320
    Reads credential / secret files (documentation of a security skill)
    const keys = fs.readFileSync(path.join(os.homedir(), '.ssh/id_rsa'), 'utf8');
    security skill
  • low Risky intent intent-offensive-security SKILL.md:3
    Offensive-security / dual-use content (legitimate for authorised testing; review intended use) (detector / deny-list definition)
    description: Scan installed OpenClaw skills for malicious code patterns including ClickFix social engineering, reverse shell (RAT), and data exfiltration. Uses OG-Text model for agentic detection.
    detector
  • low Risky intent intent-offensive-security SKILL.md:130
    Offensive-security / dual-use content (legitimate for authorised testing; review intended use)
    ### 2. RAT (Remote Access Trojan / Reverse Shell)
  • low Risky intent intent-offensive-security SKILL.md:132
    Offensive-security / dual-use content (legitimate for authorised testing; review intended use)
    - Reverse shell connections (bash -i >& /dev/tcp/, nc -e, python socket connect-back)
  • low Risky intent intent-offensive-security SKILL.md:194
    Offensive-security / dual-use content (legitimate for authorised testing; review intended use) (detector / deny-list definition)
    If the response is not valid JSON, try to extract JSON from markdown code fences. If parsing still fails and the response text contains words like "malicious", "suspicious", "backdoor", "reverse shell
    detector
  • low Risky intent intent-offensive-security SKILL.md:265
    Offensive-security / dual-use content (legitimate for authorised testing; review intended use)
    | Critical | Active exfiltration, reverse shell, or confirmed malicious payload |

A further 3 matches are quotations in this security skill's documentation and are not counted as findings.

Files scanned: 1. Evidence is masked. Grey chips explain why severity was lowered.

Against the Agent Skills spec

  • warning description-no-when description does not say WHEN to use the skill (no "use when")

Process rating: all ten parameters 51/100

  • 0Result and completion. Does not say what the result is
  • 0Inputs and preconditions. Does not say what the process needs to start
  • 0Progress reporting. Says nothing while it works
  • 30Running it twice. 5 mutating operations with no state check
  • 40Consistency. Frontmatter name (skill-scanner) differs from the folder (antivirus)
  • 60Tools and files. Uses tools (bash, web, python) that frontmatter does not declare
  • 60Failures and branches. 2 branches
  • 70When it triggers. States when to use, but not when not to
  • 100Steps. 49 steps
  • 100Execution cost. Instruction body is 3140 tokens

Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.

Quality signals

  • +5Description has no quoted example phrases that should trigger the skill
  • +4Description does not say when NOT to use the skill (false activations)
  • +3Output format is not stated: the model decides each time
  • +1No license
  • +2Single-language instructions
  • +3Description length 183: enough signal without eating the budget
  • +4Structure: 16 headings
  • +3Step-by-step instructions: 49 items
  • +4Has examples (11 code blocks)

Quality base 70; lint remarks subtract, signals add up to 100. Result: 72.