Appends arbitrary data to signed Windows executables. This is done by embedding the data at the end of the digital certificate section.

This method is described in more detail in this blog post: http:https://blog.barthe.ph/2009/02/22/change-signed-executable/

npm install exe-append

const exe = require("exe-append");
const buffer = exe.append(fs.readFileSync("my.exe"), "arbirarty data");