The European Banking Authority, a key EU financial regulator, says it has fallen victim to a hack of its Microsoft email system which the US company blames on a Chinese group.
Microsoft said last week that a state-sponsored group operating out of China was exploiting previously unknown security flaws in its Exchange email services to steal data from business and government users, believed to number in the tens of thousands so far.
The “Hafnium” group was a “highly skilled and sophisticated actor,” it said.
Hafnium has previously targeted US-based companies including infectious disease researchers, law firms, universities, defence contractors, think-tanks and NGOs, it added.
In a statement on Monday, the EBA said its investigation had found no data theft so far.
“At this stage, the EBA email infrastructure has been secured and our analyses suggest that no data extraction has been performed,” the statement said.
“We have no indication to think that the breach has gone beyond our email servers.”
The authority said the probe was still ongoing and that it has deployed additional security measures “in view of restoring the full functionality of the email servers”.
The EBA had said in a previous statement on Sunday that it had taken its email systems offline as a precaution, noting that access to personal data held on servers “may have been obtained by the attacker”.
Microsoft executive Tom Burt said last Tuesday that the company provided updates to fix the security flaws and urged customers to apply them.
“We know that many nation-state actors and criminal groups will move quickly to take advantage of any unpatched systems,” he added.
Beijing typically rejects US hacking charges out of hand and last year berated Washington following allegations that Chinese hackers were attempting to steal coronavirus research.
In January, the US said Russia was probably behind the massive SolarWinds hack that hit large swathes of the government and private sectors, and which experts say may constitute an ongoing threat.
Microsoft said Tuesday the Hafnium attacks “were in no way connected to the separate SolarWinds-related attacks.”
*Updated with new statement from EBA