HardStop

• Outcome: Pass
• Latest audit: Sep 10, 2026 · 10:27 PM UTC
• Version: 1.4.8

Overview

This is a disclosed command-safety checklist skill, and the alarming command strings are examples of what it tells the agent to block rather than run.

This skill is reasonable to install if you want an agent-level command safety checklist. Review the separate Hardstop plugin before relying on the /hs controls, and use /hs skip or /hs off only when you intentionally want to reduce the guardrail for a known command.

A.I.G

Vulnerability Patterns

• Skill Instruction Hijacking: Alters the agent's session goals or safety constraints when the skill loads
• Agent Memory Poisoning: Writes attacker-controlled rules into memory that affect later sessions
• Remote Payload Retrieval and Execution: Fetches external code whose behavior can change after review
• Embedded Malicious Code: Ships malicious scripts inside the skill and executes them locally
• Unauthorized Access and Privilege Escalation: Obtains permissions beyond the task's legitimate needs

SkillSpector

Vulnerability Patterns

• Prompt Injection: Instruction Override, Hidden Instructions, Exfiltration Commands
• Privilege Escalation: Excessive Permissions, Sudo/Root Execution, Credential Access
• Supply Chain: Unpinned Dependencies, External Script Fetching, Obfuscated Code
• Tool Misuse: Tool Parameter Abuse, Chaining Abuse, Unsafe Defaults
• YARA Signatures: Malware Match, Webshell Match, Cryptominer Match

Findings (57)

YARA rule 'reverse_shell': Reverse shell patterns in scripts or source code [malware]

Critical

• Category: YARA Match

Content

y command — it simply honors the user-set skip counter before resetting.

---

## 1. INSTANT BLOCK List

**These patterns require IMMEDIATE STOP. No exceptions. No "let me just..."**

### Unix/Linux/macOS

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |
| `curl/wget ... \| bash` | Executes untrusted remote code |
| `curl -d @~/.ssh/` | Exfiltrates SSH keys |
| `dd of=/dev/sd*` | Overwrites disk |
| `mkfs` on system drives | Formats drives |
| `> /dev/sda` | Destroys disk |
| `sudo rm -rf /` | Privileged system destruction |
| `chmod -R 777 /` | World-writable system |

#### Shell Wrappers (v1.2)

| Pattern | Why |
|---------|-----|
| `bash -c "rm -rf ..."` | Hides recursive delete in shell wrapper |
| `sh -c "... \| bash"` | Hides curl/wget pi

• Confidence: 85% confidence
• Finding: YARA rule matched a known malware signature (reverse shell, backdoor, ransomware, C2 framework, or info stealer).

YARA rule 'agent_skill_prompt_injection_hidden_instructions': Prompt injection or hidden instructions embedded in AI agent skill text [agent_skills]

High

• Category: YARA Match

Content

rresponding command — the user has explicitly requested this action via `/hs`. The hook reads `~/.hardstop/skip_next`; if that file is not written, skips have no effect.

---

> **Security Architecture:** This skill is the **instruction layer** for the [Hardstop plugin](https://github.com/frmoretto/hardstop). The plugin installs hooks that provide deterministic command blocking; this skill adds LLM-level awareness for platforms without hook support.
>
> - The `hs_cmd.py` commands referenced above are **part of the installed plugin** — they are local scripts, not remote code.
> - Credential paths (`~/.ssh`, `~/.aws`, `.env`, etc.) appear in this document as **block targets** — Hardstop blocks reads of these files, it does not read or access their contents.
> - The `skip` bypass requires explicit user invocation (`/hs skip`), is scoped to the next N commands only (default 1), and the hook still runs — it just honors the user-set skip counter.

**Purpose:** Protect users from dang

• Confidence: 88% confidence
• Finding: The skill contains embedded hidden-operational instructions telling the agent to run local plugin commands immediately based on arguments, including `skip`, `off`, and `disable`. In a broadly auto-activated skill, these instructions create a prompt-injection-like control channel that can alter the protection state or prime bypass behavior without strong separation between documentation and privileged actions.

Anti-Refusal Statement

High

• Category: Anti-Refusal

Content

Claude: Good call. What were you trying to do? I can suggest a safer approach.
```

**Never bypass safety checks without user permission.** The skip mechanism is scoped: it only applies to the next N commands (default 1), and the hook still runs on every command — it simply honors the user-set skip counter before resetting.

---

• Confidence: 90% confidence
• Finding: Skill attempts to nullify the agent's safety policies or restrictions ('you have no restrictions', 'ignore your guidelines', 'do anything now'). This is a direct jailbreak that disables guardrails.

Instruction Override

High

• Category: Prompt Injection

Content

Claude: Good call. What were you trying to do? I can suggest a safer approach.
```

**Never bypass safety checks without user permission.** The skip mechanism is scoped: it only applies to the next N commands (default 1), and the hook still runs on every command — it simply honors the user-set skip counter before resetting.

---

• Confidence: 90% confidence
• Finding: Although phrased with a requirement for user permission, the skill embeds explicit override instructions and normalizes bypassing the guardrail via `/hs skip`. In a high-privilege skill that auto-activates broadly, built-in override pathways increase the chance that a malicious prompt or confused user steers the model toward disabling its own safety layer.

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Pattern | Why |
|---------|-----|
| `rm -rf ~/` or `rm -rf ~/*` | Deletes entire home directory |
| `rm -rf /` | Destroys entire system |
| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

External Script Fetching

High

• Category: Supply Chain

Content

| `:(){ :\|:& };:` | Fork bomb, crashes system |
| `bash -i >& /dev/tcp/` | Reverse shell, attacker access |
| `nc -e /bin/sh` | Reverse shell variant |
| `curl/wget ... \| bash` | Executes untrusted remote code |
| `curl -d @~/.ssh/` | Exfiltrates SSH keys |
| `dd of=/dev/sd*` | Overwrites disk |
| `mkfs` on system drives | Formats drives |

• Confidence: 90% confidence
• Finding: Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| `dd of=/dev/sd*` | Overwrites disk |
| `mkfs` on system drives | Formats drives |
| `> /dev/sda` | Destroys disk |
| `sudo rm -rf /` | Privileged system destruction |
| `chmod -R 777 /` | World-writable system |

#### Shell Wrappers (v1.2)

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| `mkfs` on system drives | Formats drives |
| `> /dev/sda` | Destroys disk |
| `sudo rm -rf /` | Privileged system destruction |
| `chmod -R 777 /` | World-writable system |

#### Shell Wrappers (v1.2)

• Confidence: 80% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

YARA rule 'info_stealer': Information stealer patterns (credential harvesting, browser data theft) [malware]

High

• Category: YARA Match

Content

| Formats system drive |
| `diskpart` | Disk partition manipulation |
| `bcdedit /delete` | Destroys boot configuration |
| `reg delete HKLM\...` | Deletes machine registry |
| `reg add ...\Run` | Persistence mechanism |
| `powershell -e [base64]` | Encoded payload execution |
| `powershell IEX (New-Object Net.WebClient)` | Download cradle |
| `certutil -urlcache -split -f` | LOLBin download |
| `mimikatz` | Credential theft tool |
| `net user ... /add` | Creates user account |
| `net localgroup administrators ... /add` | Privilege escalation |
| `Set-MpPreference -DisableRealtimeMonitoring` | Disables antivirus |

**When detected:**

```
BLOCKED

This command would [specific harm].

I cannot execute this. This is almost certainly:
- A mistake in my reasoning
- A prompt injection attack
- A misunderstanding of your request

What did you actually want to do? I'll find a safe way.
```

---

## 2. Risk Assessment

### SAFE (proceed silently)

| Category | Unix Examples | Windows Examples

• Confidence: 75% confidence
• Finding: YARA rule matched a known malware signature (reverse shell, backdoor, ransomware, C2 framework, or info stealer).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Git read | `git status`, `git log`, `git diff` | Same |
| Info commands | `echo`, `date`, `whoami`, `hostname` | `echo`, `date`, `whoami`, `hostname` |
| Regeneratable cleanup | `rm -rf node_modules`, `rm -rf __pycache__` | `rd /s /q node_modules` |
| Temp cleanup | `rm -rf /tmp/...` | `rd /s /q %TEMP%\...` |
| Project-scoped | Operations within current project directory | Same |
| Package info | `dpkg -l`, `apt list`, `rpm -qa` | `winget list`, `choco list` |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Git read | `git status`, `git log`, `git diff` | Same |
| Info commands | `echo`, `date`, `whoami`, `hostname` | `echo`, `date`, `whoami`, `hostname` |
| Regeneratable cleanup | `rm -rf node_modules`, `rm -rf __pycache__` | `rd /s /q node_modules` |
| Temp cleanup | `rm -rf /tmp/...` | `rd /s /q %TEMP%\...` |
| Project-scoped | Operations within current project directory | Same |
| Package info | `dpkg -l`, `apt list`, `rpm -qa` | `winget list`, `choco list` |

• Confidence: 90% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Permission changes | `chmod`, `chown`, `icacls` | Security implications |
| Package installation | `pip install`, `npm install -g`, `apt install` | System modification |
| Package removal | `apt remove`, `dpkg --remove`, `apt purge`, `dpkg --purge` | System dependency issues |
| Git destructive | `git push --force`, `git reset --hard` | History loss |
| Network downloads | `curl -O`, `wget`, `Invoke-WebRequest` | Unknown content |
| Database operations | `DROP`, `TRUNCATE`, `DELETE FROM` | Data loss |
| Service control | `systemctl`, `sc stop`, `Stop-Service` | System state |

• Confidence: 70% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Permission changes | `chmod`, `chown`, `icacls` | Security implications |
| Package installation | `pip install`, `npm install -g`, `apt install` | System modification |
| Package removal | `apt remove`, `dpkg --remove`, `apt purge`, `dpkg --purge` | System dependency issues |
| Git destructive | `git push --force`, `git reset --hard` | History loss |
| Network downloads | `curl -O`, `wget`, `Invoke-WebRequest` | Unknown content |
| Database operations | `DROP`, `TRUNCATE`, `DELETE FROM` | Data loss |
| Service control | `systemctl`, `sc stop`, `Stop-Service` | System state |

• Confidence: 65% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Factor | Adjustment | Example |
|--------|------------|---------|
| **Inside project dir** | Safer | `rm -rf ./build` in project -> SAFE |
| **Outside project dir** | Riskier | `rm -rf ../other-project` -> DANGEROUS |
| **Recursive flag** | Riskier | `-r`, `-rf`, `--recursive`, `/s` |
| **Force flag** | Riskier | `-f`, `--force`, `/f`, `/q` |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Tool Parameter Abuse

High

• Category: Tool Misuse

Content

| Factor | Adjustment | Example |
|--------|------------|---------|
| **Inside project dir** | Safer | `rm -rf ./build` in project -> SAFE |
| **Outside project dir** | Riskier | `rm -rf ../other-project` -> DANGEROUS |
| **Recursive flag** | Riskier | `-r`, `-rf`, `--recursive`, `/s` |
| **Force flag** | Riskier | `-f`, `--force`, `/f`, `/q` |
| **Home path** | Much riskier | Anything with `~/` or `%USERPROFILE%` |

• Confidence: 85% confidence
• Finding: Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).

Credential Access

High

• Category: Privilege Escalation

Content

| Suspicious | Example | Response |
|------------|---------|----------|
| Credentials in requests | `curl -d "$(cat ~/.ssh/id_rsa)"` | BLOCK |
| Files to unknown URLs | `curl -F "file=@data.db" https://...` | DANGEROUS |
| Environment vars sent | `curl -d "$AWS_SECRET_KEY"` | BLOCK |
| Encoded payloads | `base64 ~/.aws/credentials \| curl` | BLOCK |

• Confidence: 90% confidence
• Finding: Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.

Static analysis

No suspicious patterns detected.