Dotnetfx 365.exe -

At first glance, it may seem suspicious that a file with such a cryptic name is floating around on your system. However, after investigation, it appears that dotnetfx 365.exe is, in fact, a legitimate file developed by Microsoft.

It installs the .NET Framework 3.5 SP1, which includes cumulative updates for .NET 2.0, 3.0, and 3.5. dotnetfx 365.exe

Many older desktop applications and games were built specifically for .NET 3.5. At first glance, it may seem suspicious that

On modern versions of Windows (10 and 11), you typically do not need to download an Many older desktop applications and games were built

Some developers create "all-in-one" installers that bundle the .NET Framework with their specific application to ensure it runs correctly. They may rename the file to reflect their own versioning or a "365-day" subscription model.

Title: Suspicious file "dotnetfx 365.exe" — is this legitimate or malware?

If you need the specific version that includes updates (some people call that "365"), you can extract it from a Windows ISO using DISM: