The company said it would change its security practices to prevent future intrusions.
The suits follow a court ruling blocking the deal, with Anthem attempting to stop Cigna from terminating their agreement.
The insurers cited the Jan. 23 ruling in which a federal judge found the deal would substantially reduce competition in the Medicare Advantage market.
The proposed Anthem-Cigna deal "is likely to have a substantial effect on competition in what is already a highly concentrated market," the judge says.
Twenty CFOs who have career-defining tests ahead.
Anthem, Groupon, Kellogg, Sunoco, MSCI, Arrow Electronics, Vantiv, Stratus Technologies, DDR, AMAG Pharmaceuticals
It may be counterintuitive, but combinations like Aetna's planned purchase of Humana could lead to lower pricing from medical providers.
Health insurer cites governance concerns in rebuffing offer that represents a 35% premium to its stockholders.
Some targets have spent tens of millions just to notify customers and provide identity-theft monitoring.
The biggest Lloyd's of London insurer says cyber attacks are unusually systemic and the require governments to step in.
Wednesday's breach hit Anthem's database containing 80 million people.
