Is this shell script safe?
Paste code before you run it. We'll explain what it does and flag suspicious behavior.
Paste code on the left and press Check Code.
The scanner reports:
- network requests and the hosts they contact
- file reads, writes and deletions
- shell command execution
- code built and executed at runtime
- access to cookies, credentials, clipboard and keystrokes
- persistence, privilege changes and security tool tampering
- encoded payloads and obfuscation
Findings are separated into capabilities (what the code can do) and suspicious behaviour (patterns typical of malicious scripts), because using the network is not the same as stealing data.
Static checks run locally in your browser. Nothing is uploaded, logged or stored.
Press Ctrl/Cmd + Enter to check.
How it works
Install instructions that say to pipe a URL into bash hand complete control of your machine to whoever operates that server. Paste the script or the one-liner and see exactly what it touches.
- The language is detected from the code, and you can override it in the dropdown.
- JavaScript and TypeScript are parsed into an abstract syntax tree, so function calls, imports and property accesses are matched structurally rather than as text. Python, PowerShell and shell are scanned with rules that first mask comments and string contents. HTML is scanned tag by tag, with inline scripts handed to the JavaScript analyzer.
- Findings are split into capabilities (what the code can do) and suspicious behaviour (patterns typical of malicious code).
- Behaviour chains are evaluated: reading cookies is one thing, reading cookies and posting them to a hardcoded host is another.
- A risk level is assigned, every finding links to its line, and you can optionally ask an AI model to explain the result in prose.
What it detects
- curl or wget piped into bash, sh, python, perl or node
- downloads followed by chmod +x and execution
- netcat, socat and /dev/tcp connections used for reverse shells
- reads of /etc/shadow, ~/.ssh keys, ~/.aws/credentials, .netrc and wallet files
- keys appended to authorized_keys, which grants permanent remote access
- cron jobs, systemd units and shell profile hooks used for persistence
- sudoers edits, setuid bits and admin group changes
- history clearing, firewall disabling and log deletion
- rm -rf on root paths, mkfs, dd to a raw device and fork bombs
Privacy: your code stays in your browser
The whole static analysis, including parsing, rule matching and risk scoring, is compiled into the page and runs on your machine. No request is made when you press Check Code, nothing is logged and nothing is stored. The only exception is the optional AI explanation: it is off by default, and when you tick the box the code is sent to the configured AI provider for that single request.
Why we never say "this code is safe"
Nobody can prove a piece of code is harmless by inspecting it. Code can fetch its real payload at runtime, behave differently on another machine, or hide its intent in a dependency you cannot see. So the verdict is always one of four: low apparent risk, potential risk, high risk, or unable to determine. "Low apparent risk" means these particular patterns are absent — nothing more.
Frequently asked questions
- Is curl | bash always dangerous?
- It is always a risk you should take deliberately. The content is fetched and executed without you seeing it, it can differ per request or per user agent, and it usually runs with sudo. Download the script, read it, then run it.
- Why is a plain sudo reported?
- Because elevated commands have no limits on what they can change. It is reported as a capability so you know which parts of the script run as root, not as a suspicious finding.