Comment by spajus

I had something similar happen with a translations file for a game. It has a column with keys like "created.at" and a column with human readable translation. Google Sheets automatically create links to anything that looks like an URL, so "created.at" becomes a link. And if you're not careful to immediately remove those auto created links, some of them can lead to malicious sites, then Google will detect your sheet containing those malicious links. In my case Google blocked sharing, but didn't take the document down. Still, I believe it's terrible UI/UX, to automatically link to malicious sites and then penalize the sheet owner for this.