Why is my game flagged by antivirus?

Almost always a false positive: your game is flagged because it's unsigned (no code-signing certificate, so it's less trusted), has low reputation (a new, uncommon executable few people have run safely yet), or uses packers/obfuscation or behaviors that trigger antivirus heuristics (which often resemble malware). It's not actually malware, antivirus is reacting to trust signals, which you can address.

How do I stop antivirus and SmartScreen from blocking my game?

Code-sign your builds with a valid code-signing certificate, this is the most important fix, since signed software is far more trusted by antivirus and Windows SmartScreen and resolves many flags. Build reputation over time (signing accelerates it), avoid packers/obfuscation that trigger heuristics, and report any persistent false positives to the antivirus vendors so they whitelist your game.

Why does my new indie game get flagged but established games don't?

Because of reputation: antivirus and SmartScreen trust software that many users have run safely, and a new indie game's executable starts with no reputation, so it's treated with suspicion until it earns trust. Established games have accumulated reputation. Code-signing your build establishes authenticity and accelerates reputation-building, which is why signing is the key fix for a new game starting from zero reputation.

How to Fix a Game Flagged by Antivirus on Launch

Quick answer: When antivirus flags your game on launch, it's almost always a false positive: the game is flagged or blocked as a potential threat because it's unsigned (no code-signing certificate), has low reputation (a new, uncommon executable few people run), or uses packers/obfuscation or behaviors that trigger antivirus heuristics. Fix it by code-signing your builds, building reputation, avoiding heuristic-triggering packers, and reporting false positives to antivirus vendors.

Having your game flagged by antivirus, or blocked by Windows SmartScreen, is alarming and damaging: players see a security warning about your game and may not run it. It's nearly always a false positive (your game isn't actually malware), triggered by signals antivirus uses to assess unknown software. Fixing it is about removing those signals, primarily by signing your build and building trust.

Why Antivirus Flags Legitimate Games

Antivirus and OS protections (like SmartScreen) assess unknown executables for risk using several signals, and a legitimate game can trip them. Unsigned executables, a build without a valid code-signing certificate is inherently less trusted, antivirus and SmartScreen treat unsigned software with more suspicion, a major cause of warnings. Low reputation, reputation systems trust software that many users run safely; a new or uncommon executable (like an indie game few people have run yet) has low reputation and gets flagged until it builds trust. Heuristic triggers, certain behaviors or characteristics, packers/obfuscation (often used by malware, so they trigger heuristics), or behaviors that resemble malware, cause false positives.

So a flagged game is usually a false positive driven by being unsigned, new/uncommon, or using something that resembles malware to a heuristic, not because it's actually malicious. The fix is to address these trust signals.

How to Diagnose It

Note what's flagging it and how, a specific antivirus, or Windows SmartScreen, and whether it's a hard block or a warning. Check whether your build is code-signed (unsigned is a prime cause), whether it's a new/low-reputation executable (likely if your game is new), and whether you're using packers or obfuscation that could trigger heuristics. The specific antivirus's detection name (if shown) can hint at why (a generic heuristic detection suggests a false positive from heuristics).

Player reports of antivirus warnings or SmartScreen blocks are the signal, and they may concentrate around launch (when the executable is newest and least-reputation). This is a distribution/trust issue rather than an in-game bug, so it's diagnosed from how and where the flagging happens, not from runtime behavior.

How to Fix It

Address the trust signals. Code-sign your builds, sign your executable with a valid code-signing certificate, this is the most important fix, as signed software is far more trusted by antivirus and SmartScreen and signing alone resolves many flags (and an EV certificate or building signing reputation helps even more). Build reputation, reputation grows as more users run your signed software safely over time, so flags often diminish as your game becomes known (signing accelerates this). Avoid heuristic triggers, avoid packers/obfuscation that resemble malware, since they trigger antivirus heuristics. Report false positives, submit your game to antivirus vendors as a false positive so they whitelist it.

Code signing is the foundational fix, it establishes your build's authenticity and dramatically reduces false flags. After signing (and reporting any persistent false positives), verify the warnings diminish. Because antivirus flags hurt installs and trust (players are scared off by security warnings), addressing them, primarily through code signing and reputation, is important for distribution, especially for a new indie game whose executable starts with no reputation.

Antivirus flagging your game is almost always a false positive from being unsigned, new, or heuristic-triggering. Code-sign your builds (the key fix), build reputation, and report false positives.