US President Joe Biden has launched an investigation into a widespread cyber attack on Microsoft’s email services that may have compromised tens of thousands of businesses.
The attack, which was first uncovered last week, has taken advantage of previously undiscovered vulnerabilities in Microsoft’s mail server software to potentially gain access to swathes of organisations in Asia and Europe.
The European Banking Authority, which regulates lenders in the EU and stores vast quantities of sensitive data, today became the latest victim to reveal it had been targeted by the attack.
The White House is launching a government-wide response to the attack, which Microsoft has blamed on a hacker group with links to the Chinese state.
US officials yesterday urged businesses to take further steps to gauge whether their systems had been targeted, warning there was still an “active threat”.
Microsoft has issued emergency patches in an effort to halt the attack, but companies are still thought to be vulnerable.
“We can’t stress enough that patching and mitigation is not remediation if the servers have already been compromised, and it is essential that any organisation with a vulnerable server take measures to determine if they were already targeted,” a White House official said.
Organisations affected appear to run web versions of Microsoft Outlook and host them on their own machines, rather than relying on cloud providers.
This could mean larger organisations and government agencies have been spared, Reuters reported, citing reports from the investigation.
The incident comes shortly after Russian hackers breached a string of major US companies and government agencies after targeting vulnerabilities in Solar Winds software.
Microsoft has said there is no evidence of any connection between the two attacks.