It's common for software licenses to prohibit decompiling and reverse engineering. This is often to protect intellectual property rather than to hide malicious content. If they wanted to share the code freely, they'd open-source it. That doesn't mean that all closed-source programs are malicious.
I'm not saying it's malicious, I'm saying that there needs to be at least a password to the exe, an actual license file as well as other issues that need to be worked out as well. I get it's closed-source but doesn't mean that there's anything stopping someone from extracting it and/or making a malicious copy of it.