Can a company legally depress their stock price in order to supercharge their buyback program?

Let’s say a company thinks their stock is undervalued. So they start a share buyback program. Before they actually start buying, they tell the world that the company is in trouble and going to lose revenue etc, so the share price drops, and they get to buy back more shares.

Is this legal? Presumably one cannot fiddle with the financial report because it’s audited, but it might be possible to give weaker guidance.

If it is legal, has it actually been done in the past?