Big-Name Targets Push Midnight Blizzard Hacking Spree Back Into the Limelight

Microsoft and Hewlett-Packard Enterprise (HPE) both recently disclosed that they suffered corporate email breaches at the hands of Russia’s “Midnight Blizzard” hackers.

The group, which is tied to the Kremlin’s SVR foreign intelligence, is specifically linked to SVR’s APT 29 Cozy Bear, the gang that meddled in the United States 2016 presidential election, has conducted aggressive government and corporate espionage around the world for years, and was behind the infamous 2021 SolarWinds supply chain attack. While both HP’s and Microsoft’s breaches came to light within days of each other, the situation mainly illustrates the ongoing reality of Midnight Blizzard’s international espionage activities and the lengths it will go to to find weaknesses in organizations’ digital defenses.

“We shouldn’t be surprised that Russian intelligence-backed threat actors, and SVR in particular, are targeting tech companies like Microsoft and HPE. With organizations that size, it would be a much bigger surprise to learn they weren’t,” says Jake Williams, a former US National Security Agency hacker and current faculty member at the Institute for Applied Network Security.

HP Enterprise said in a US Securities and Exchange Commission submission posted on Wednesday that Midnight Blizzard gained access to its “cloud-based email environment” last year. The company first learned about the situation on December 12, 2023, but said that the attack began in May 2023. Hackers “accessed and exfiltrated data … from a small percentage of HPE mailboxes belonging to individuals in our cybersecurity, go-to-market, business segments, and other functions,” the company wrote in the SEC filing. HP Enterprise said the breach likely came about as the result of another incident, discovered in June 2023, in which Midnight Blizzard also accessed and exfiltrated company “SharePoint” files beginning as early as May 2023. SharePoint is a much-targeted cloud collaboration platform made by Microsoft that integrates with Microsoft 365.

“The accessed data is limited to information contained in the HPE users’ email boxes,” HP Enterprise spokesperson Adam Bauer told WIRED in a statement. “We continue to investigate and analyze these mailboxes to identify information that could have been accessed and will make appropriate notifications as required.”

Meanwhile, Microsoft said on Friday that it detected a system intrusion on January 12 tied to a November 2023 breach. The attackers targeted and compromised some historic Microsoft system test accounts that then allowed them to access “a very small percentage of Microsoft corporate email accounts, including members of our senior leadership team and employees in our cybersecurity, legal, and other functions.” From there the group was able to exfiltrate “some emails and attached documents.” Microsoft noted in its disclosure that the attackers appeared to be seeking information about Microsoft’s investigations and knowledge of Midnight Blizzard itself.

“The attack was not the result of a vulnerability in Microsoft products or services. To date, there is no evidence that the threat actor had any access to customer environments, production systems, source code, or AI systems,” the company wrote in its disclosure. “This attack does highlight the continued risk posed to all organizations from well-resourced nation-state threat actors like Midnight Blizzard.”

In an August 2022 report from the threat intelligence firm Mandiant, incident response leader Doug Bienstock wrote that the firm “continues to identify APT29 operations targeting the United States’ (US) interests, and those of NATO and partner countries.” He noted that even though the hacking group is widely known, it has continued to be “extremely prolific” and returns to target certain victims multiple times over months or even years. “This persistence and aggressiveness are indicative of sustained interest in this information and strict tasking by the Russian Government,” Bienstock wrote, adding, “Mandiant has observed APT29 continue to demonstrate exceptional operational security and advanced tactics targeting Microsoft 365.”

While Midnight Blizzard is far from a new threat, researchers point out that it’s always productive to have renewed attention on the issue of persistent state-backed espionage. Williams, of the Institute for Applied Network Security, also highlights the hackers’ counterintelligence goals in the recent Microsoft breach—that Midnight Blizzard appeared to be specifically interested in learning what company executives know about their group and methods.

"I’m not surprised that the threat actors were observed looking for what information Microsoft had on them,” Williams says. “But it’s a great piece of evidence to remind us that threat actors are regularly monitoring our own investigative efforts as defenders.”