Two people familiar with the matter told news outlet Reuters that BlackCat, which operates as a ransomware-as-a-service group, was behind the Feb. 21 cybersecurity incident on Change Healthcare. Few details have been released about the nature of the cybersecurity issue, and BlackCat's claims have yet to be confirmed by Change Healthcare. But a Feb. 21 Securities and Exchange Commission filing from UnitedHealth Group, Change's parent company, stated that "a suspected nation-state associated cyber security threat actor" had gained access to some Change IT systems. A Feb. 26 update on Optum's website indicates that the Change Healthcare incident, which has disrupted the organization's payment and pharmacy processing operations, is still ongoing. "We are working on multiple approaches to restore the impacted environment and will not take any shortcuts or take any additional risk as we bring our systems back online," the update reads.