its a "false" detect. Well half at least. Malware and Viruses often try to hide their signature and code too fool or hide from Anti Virus programs. Therefore Confusers are used, who just make it harder to reengineer software.
Sadly as small developers such Confuser Programs are necessary to protect your code. Therefore under certain circumstances the Anti Virus Programs detect them as warnings, depending on the functions and degree you use to protect your software.
For example see this post: https://github.com/yck1509/ConfuserEx/issues/153 the last post. Confuser is one of those protection programs for developers.
You can also read the definition of the Virus by your AntiVirus software. As you see they are only flaged for hiding the code. There is nothing harmful, its just to protect code from being changed or reengineered.