The group, which has almost a 15% share of the media company, have been trying to overthrow the company's board for three months.
Jana believes it can increase earnings by selling more ads and highlighting CNET'S listings in Internet search results.
The document also questions the competence of the company's chief executive, Neil Ashe, and chief financial officer, Zander Lurie. The Jana group argued the men's background in investment banking makes them poor choices to lead an online media company.
CNET said the Jana group's analysis contains "numerous misstatements" and "is misleading in many respects," according to The Associated Press. Still, the company said it will carefully review Jana's suggestions and "respond in due course."