Is it best to keep where you work confidentially. ?

I have a co-worker who’s going through hell right now because a relative of his got jealous that he got a good job opportunity. His relative emailed the higher ups at his job with false claims about him. Thankfully his management team were loyal and forwarded the emails to him. It had very petty information about him like how he’s incompetent of his job because he cheated in class when he was in school, and even false claims about his personal life. It was clear that his relative was jealous and spiteful so he didn’t lose his job. But his situation makes me cautious of telling ppl where I work specifically because I too have a lot of jealous and hateful relatives. My question to you is, are you comfortable with telling ppl where you work specifically (name of company) if they ask?