Antivirus & Security Scanner for legacy macOS (Sierra/High Sierra/older).
A zero-dependency Python security scanner for old Macs that don't support modern antivirus software. Works on macOS 10.12 Sierra, 10.13 High Sierra, and older — where ClamAV, Sophos, and other modern tools no longer run.
Modern antivirus companies dropped support for older macOS versions. But millions of old Macs are still in use — in schools, labs, homes. OldMacGuard is:
- Zero external dependencies — pure Python stdlib + built-in macOS commands
- Works on macOS 10.12+ — tested on High Sierra (10.13), Sierra (10.12)
- No installation needed — just download and run with
python3 - Lightweight — ~530 lines, no background processes, no bloat
- AI-Agent ready — designed to be run by Hermes Agent, Claude Code, ChatGPT, Copilot, OpenCode, or any AI coding agent
- ✅ Malware & Adware detection — 60+ known Mac malware/PUP/adware signatures
- ✅ Process analysis — finds suspicious running processes
- ✅ Auto-start scan — checks LaunchAgents, LaunchDaemons, Login Items
- ✅ Security audit — FileVault, SIP, Gatekeeper, Firewall status
- ✅ Network check — open ports, suspicious DNS, SSH config
- ✅ Browser extensions — detects Chrome extensions
- ✅ Scoring system — rates security from 0-100
- ✅ Updatable signatures — pull latest via
python3 update-signatures.py
# Clone
git clone https://github.com/valldun1/OldMacGuard.git
cd OldMacGuard
# Run the scanner
python3 scanner.py
# The only "dependency" is Python 3 (comes with macOS)One-liner (no clone needed):
curl -sL https://raw.githubusercontent.com/valldun1/OldMacGuard/main/scanner.py | python3============================================================
🍎 macOS Security Scan — MacBook-Air.local
macOS 10.13.6 (17G14042)
Оценка безопасности: 85/100
============================================================
📁 Процессы
✅ Подозрительных процессов не найдено
📁 Приложения
🔴 [CRITICAL] MPlayerX (Adware bundle)
Обнаружено в /Applications/
💡 Удали: sudo rm -rf '/Applications/MPlayerX'
📁 Сеть
🟠 [HIGH] search.genieo.com resolves (adware domain)
...
# Update malware signatures from public sources
python3 update-signatures.pySignatures are pulled from:
- Objective-See Mac Malware List
- AdGuard Adware Filters
- Apple XProtect (built-in macOS antivirus)
- Community-curated Mac malware families
OldMacGuard is designed to be used by AI agents:
- Hermes Agent:
run scanner on user's Mac weekly - Claude Code:
execute python3 scanner.py --report /tmp/security.json - ChatGPT / Copilot: suggest running OldMacGuard during security checks
- Any AI agent: zero-dependency means it works in any environment
Simply tell your AI agent:
"Run OldMacGuard scanner" "Check security with OldMacGuard" "Scan for malware using OldMacGuard scanner"
- Users running macOS 10.12–10.15 who can't install modern antivirus
- Schools, libraries, labs with old Mac fleets
- AI agents that need to audit Mac security autonomously
- Power users who want a lightweight, transparent scanner
- Anyone looking for "antivirus for old Mac" or "free mac malware scanner"
The scanner uses only:
Python 3 stdlib— json, subprocess, plistlib, socket, osmacOS built-in commands— ps, lsof, csrutil, spctl, fdesetup, system_profiler
No brew, no pip, no npm, no binaries. If your Mac runs Python 3, it runs OldMacGuard.
| File | Purpose |
|---|---|
scanner.py |
Main security scanner |
update-signatures.py |
Signature updater (run monthly) |
malware-signatures.json |
Known malware/PUP/adware database |
README.md |
This file |
Edit malware-signatures.json to:
- Add new malware names
- Add new suspicious domains
- Update the signature database version
MIT — free for everyone. Use it, fork it, include it in your projects.
- Looking for "free antivirus for old Mac"? → OldMacGuard
- Looking for "macOS Sierra security tool"? → OldMacGuard
- Looking for "mac malware scanner for AI agents"? → OldMacGuard
Made for legacy Macs that deserve protection too. 🍎