Imidef Blog

Installing LuLu on Mac: Your First Defense Against Infostealers

Install LuLu firewall on Mac

Setting up a new Mac is exciting, and it is the perfect time to lock down security. In 2025, infostealers are a real threat: malware that silently grabs logins, passwords, cookies, and even card data. Macs are targeted too, so adding an outbound firewall is a smart first step.

My pick: LuLu, a free and open source firewall from Objective-See.

Why LuLu?

  • Free and open source: Transparent, actively maintained, and trusted by the Mac security community.
  • Blocks suspicious outbound traffic: When an app tries to connect to the internet, LuLu prompts you to allow or deny it.
  • Lightweight and Mac-friendly: Runs quietly in the background without slowing down your machine.

How to Install LuLu (Fast)

  1. Download the latest build from the Objective-See site.
  2. Open the .dmg and drag LuLu to your Applications folder.
  3. Launch LuLu and grant the requested permissions (admin password, system extension).
  4. In Settings, enable "Alert on new outgoing connections."

That is it; installation takes about five minutes.

Recommended Settings

  • Default-deny for new apps: Only allow connections you recognize and trust.
  • Create allow rules for essentials: Safari, App Store, VS Code, your password manager, etc.
  • Review prompts carefully: Check the app name, path, and destination domain before allowing.
  • Use temporary allows when unsure: Let it through once, then revisit the logs to decide.

Tip: Open LuLu's Rules or Log Viewer anytime to review what's talking to the internet.

What LuLu Does (and Does Not) Do

  • Does: Monitor and block unauthorized outbound connections from apps and processes.
  • Does not: Replace antivirus, detect all malware, or manage inbound macOS firewall rules.

Use LuLu alongside built-in macOS protections (Gatekeeper, XProtect) and good habits (no pirated apps, install from trusted sources, keep macOS updated).

Everyday Experience

  • The first day, expect prompts from common apps (Safari, VS Code, etc.).
  • Once you allow a trusted app, LuLu remembers, so prompts fade quickly.
  • The biggest win is peace of mind: you can block unknown or unexpected connections instantly.

Bottom Line

Macs are safer than most PCs, but they are not immune. With infostealers on the rise, controlling outbound traffic is a practical, beginner-friendly layer of defense. LuLu's "only allow what you need" approach makes it an ideal first security install on a new Mac.

👉 Related: How to Use GPT‑5 in VS Code