AI Decompilation Is Cheap Now: What It Means for Closed-Source Security

What was reported

On 14 October 2026, Simon Willison highlighted a post by indie game developer Popcar titled "AI is mass decompiling games. That's both awesome and scary." Popcar describes a recent wave of AI-powered decompilation of existing games. The upsides are unusual mashups between games and a boom in preservation projects that get old games running on new hardware, often in a browser using WebAssembly.

The downside is the one Popcar calls out as already widely understood. If AI can decompile games and software, the argument goes, then anybody can decompile other software and use it however they like. Competitors could also copy paid products. Popcar pairs this with the preservation case: with digital-only sales and shutting-down servers, people may be able to keep running software they bought.

Why this matters beyond games

Games are a visible example, but the underlying shift is about the cost of reverse engineering. Decompilation has always been possible. It was slow, specialist work, and that friction quietly did a lot of defensive work for vendors. If AI collapses that cost, the friction goes away for everyone, including people with no intent to preserve anything.

This is our analysis rather than a claim from the source, but the implications for security teams are fairly direct.

Practical implications for security teams

• Assume the binary is readable. Anything shipped to a client, whether a desktop app, mobile app or embedded firmware, should be treated as inspectable. API keys, signing secrets and hard-coded credentials in a compiled artefact were never safe, and they are less safe now.
• Move trust decisions server-side. Licence checks, entitlement logic and anti-abuse rules that rely on the client being opaque are the first to erode.
• Revisit obfuscation as a control. Obfuscation raises cost, and that cost is now lower. It can still slow casual copying, but it should not appear in a threat model as a confidentiality guarantee.
• Expect faster attacker analysis of your updates. Easier binary comprehension makes it cheaper to study a vendor patch and work out what it fixed, so the window between a fix shipping and your deployment of it matters more.
• Use the same capability defensively. Reviewing third-party binaries, legacy components with no source, and suspicious dependencies becomes more tractable for blue teams too.

The legal and governance angle

Popcar's framing also points at an open question: who decides what reuse of decompiled code is acceptable? Preservation advocates and rights holders will disagree. Organisations that ship proprietary software should review their licence terms and assume that technical barriers will not be what stops copying. Organisations that consume software should record which components they cannot inspect from source and whether they are comfortable with that.

What we would not conclude

The source is a developer's perspective on a trend, not a measurement of how accurate or widespread AI decompilation is across software in general. We would not infer that any specific product is exposed, or put numbers on how much faster reverse engineering has become. What the account does establish is the direction of travel, and that it is already being used at scale on games.