Are you a science fiction author?

Are you about to use IM to talk dirty to someone?

Are you using "cyber" to replace the word "computer" or "network" for a bad or nonexistent reason? (e.g. "cybersecurity" instead of "network security")

Are you using the term to saber-rattle and/or fear-monger in order to secure funding for your corner of the military industrial complex?

You're probably okay.
Then yes, using "cyber" will make you look like an idiot. But you have other things to feel embarrassed about.
Then I have no idea what you intend to use "cyber" for (unless you're about to misspell "Siberia"). So it's hard to say, but the odds are good that you're about to make a fool of yourself.
Actually, you will probably not look like an idiot to the credulous legislators you're bullying into handing you money.

But the rest of us think you're a dangerous moron.