UnitedHealth Group ( UNH ) has had a difficult two years marked by a severe cyberattack that was followed by the killing of a senior executive, an earnings miss and leadership turnover, the disclosure of civil and criminalAnalyst’s Disclosure:I/we have no stock, option or similar derivative position in any of the companies mentioned, and no plans to initiate any such positions within the next 72 hours. I wrote this article myself, and it expresses my own opinions. I am not receiving compensation for it (oth ...