upx VS fpm

According to this source:

Following optimization, tools like UPX can compress the resulting binary, significantly reducing file size. This compression is invaluable for resource-constrained environments but adds a decompression step during binary execution.

I have been using UPX but I'm quite sure if there's something out there that offers better compression.

Ah that's nice, long ago I used parchment.js to load a inform7 created z5 file on my website. You could try to compress your executable with upx https://upx.github.io/

In this process, the given packer tool embeds a natively compiled PE into another executable that contains the information needed to unpack the original content and execute it. Perhaps the most well known packer, which is not even for malicious purposes, is Golang's UPX package.

Rewrite in C#, and use an obfuscator on the DLL. You can also write some parts in C++ as many variable and function names are forgotten when compiling. You should also encrypt the PCK, and see if you can embed it. If it's embedded, you can make it more annoying to deal with by packing it with https://upx.github.io/

Another good example of false positives like this would be binaries that are compressed with UPX - the way it works is apparently very similar to how stub-loader malware operates and signature detection tools will flag it as malicious.

This will optimise the release binary to be as small as possible. Additionally with upx we can create really small docker image !

Then I compressed it with upx, cp small.exe smallUpx.exe && upx --brute smallUpx.exe, got a 10752 bytes executable, half the size, but still pretty large

If you ever revisit that decision, check out FPM. It can shave off a few of the rough edges related to packaging: https://github.com/jordansissel/fpm

The easiest way is probably FPM: https://fpm.readthedocs.io/en/latest/

There is definitely a lot more to building a proper package for wider distribution, but there are some great tools out there for folks wanting to get into it that make it more approachable. I've done my fair share with fpm when learning how the proverbial sausage is made.

Check out https://github.com/jordansissel/fpm

I use RedHat based environments for work. I've had good success creating my own yum repo and building RPM packages with Effing package management. FPM can handle packages for most distros so if you want to publish a linux app it is an easy way to provide it in multiple formats.