Here are the things that are considered to be unethical in project management:
- Framing/Scapegoating your team members or other managers
- Withholding critical information that is vital to the project
- Creating a fictitious company whose main purpose is to supply materials for the project, and directly or indirectly benefiting from this company
- Using your power in the project to pursue illegal activities
- Force team members to do things that they are not comfortable with
I know for a fact that bribes are the norm, rather than the exception, in some parts of the world, but they are still unethical as they are always done under the table.
If something is wrong somewhere in the business world, then it's wrong everywhere. We live in a highly connected world, let's not forget about that!