Steve Orr has a follow-up on the Excellus BlueCross BlueShield data breach that was disclosed in September, but the scant details still available will doubtless continue to frustrate those who want to know how the breach occurred and why it took almost 20 months for Excellus to detect it. And the available facts serve as a reminder that encryption does not prevent all breaches.
The Excellus breach was one of the largest in the healthcare sector, affecting over 10 million members and their dependents. It may also have impacted Highmark BlueCard holders who obtained services from Excellus providers. The initial attack reportedly occurred on December 23, 2013, but was not detected until August, 2015.
By now, about a dozen lawsuits have been filed against Excellus and its parent company, Lifetime Healthcare.
From the git-go, Excellus claimed that this was a “sophisticated” attack. And while that phrase may be over-used, frankly, if Mandiant is having problems figuring out what happened and how, Excellus may be right.
Unlike some other big breaches in the healthcare sector, spear phishing does not appear to have been involved in obtaining employee passwords, at least according to an Excellus spokesperson. But however they got in, the attackers were able to plant malware on the systems that enabled acquisition of employee login credentials. Orr reports:
The user accounts that were compromised at Excellus were of employees with high-level administrative access, which allowed them to roam freely through company data. The company told Nozzolio that the hackers could have unlocked any encrypted data they found “because of the type of access the attacker possibly had.”
Forensic analysis by Mandiant indicated that the hackers maintained access until May 11, 2015. It’s not clear what may have happened on that date that prevented further access.
Even then, Excellus did not become aware of the intrusion for another three months, until August 5, 2015. They announced the breach on September 9, 2015.
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