Why New Launchers Trigger SmartScreen & Antivirus (And Why Eclipse Is Safe)
If Windows warned you or your antivirus flagged Eclipse, you're not alone — and it's not what it looks like. Here's an honest, technical explanation of exactly what's happening.
We'd rather over-explain this than have you wondering. If Windows SmartScreen warned you when installing Eclipse, or your antivirus flagged it, here's exactly why — no hand-waving.
Why SmartScreen warns you
Windows SmartScreen isn't a virus scanner. It's a reputation system. When software is brand new and hasn't been downloaded by many people yet, SmartScreen doesn't recognize it and shows a "Windows protected your PC" warning — regardless of whether the software is actually safe. Every new launcher, from every new developer, hits this until it builds up download history.
To proceed, click More info → Run anyway. As more people install Eclipse, this warning goes away on its own.
Why a couple of engines might flag it
You may see one or two antivirus engines flag the installer. Here's the important part: they're AI/heuristic detections (you can spot them by the !ml or ml.score label), not real virus signature matches. Heuristic engines don't compare against a database of known malware — they guess based on behavior patterns. And Eclipse does a few things that look unusual to a guessing algorithm but are completely normal for a launcher:
- It launches Java to run the game.
- It writes to your AppData folder to store game files and settings.
- It updates itself.
Those three behaviors are exactly what a launcher is supposed to do — and also, coincidentally, things a heuristic engine treats as suspicious when the software is unsigned. That's why Microsoft's ML flag reads Wacatac.C!ml — the !ml tells you it's a machine-learning prediction, not a signature match. Every traditional, signature-based engine (Kaspersky, Bitdefender, ESET, Malwarebytes, and the rest) reports Eclipse as clean.
The real fix: code-signing
Both of these clear up with a code-signing certificate, which cryptographically proves the software comes from us and hasn't been tampered with. Signing certificates are expensive for a new project, but it's on our roadmap as Eclipse grows — and it's the single thing that removes both the SmartScreen warning and the heuristic flags.
How to verify for yourself
We don't ask you to take our word for it. Every release is uploaded to VirusTotal and scanned by dozens of engines — you can see the full report and the exact breakdown on our Security page. Transparency is the whole point.
If anything ever looks off to you, tell us on Discord. We'd rather answer a hundred questions than leave one person guessing.