Any government agency or corporation using SharePoint Server is reportedly at risk

Hackers have exploited a major security flaw in Microsoft's SharePoint software to breach document-sharing systems used by government agencies and businesses worldwide, the Washington Post reported Monday, citing state officials and private researchers.

The attack, which unfolded over the past several days, targeted organizations in the US, the EU, China, and Brazil. The hackers leveraged a previously unknown vulnerability that allowed them to steal cryptographic keys, giving them access to sensitive systems even after reboot. The flaw remained undetected despite Microsoft's latest security update just two weeks earlier.

"Anybody who's got a hosted SharePoint server has got a problem," Adam Meyers of cybersecurity firm CrowdStrike said, describing the issue as "a significant vulnerability." It was not immediately clear who is behind the hack attack, the Washington Post noted.

Microsoft acknowledged the breach and said it was working with the US Department of Homeland Security and the Department of Defense to contain the damage. As there is currently no fix available, the company advised affected customers to disconnect their servers from the internet.

The latest hack attack adds to a wave of concern about Microsoft's ability to secure its software. One of the world's most entrenched vendors of government software, the company has suffered a series of embarrassing failures over the past two years, including breaches of its corporate networks and the email accounts of top executives.

Governments worldwide have sought to reduce dependence on Western technology providers and assert greater digital sovereignty, not only to guard against cybersecurity risks, but also to shield their digital infrastructure from the geopolitical leverage of the US.

The EU has accelerated efforts to curb reliance on American cloud and AI services, backing domestic alternatives and exploring procurement mandates. China is pursuing a sweeping campaign to replace foreign hardware and software by 2027.

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Russia, which views US tech as a national security threat, is developing isolated systems and promoting state-run platforms. Microsoft, which suspended new software sales in Russia following the escalation of the Ukraine conflict in 2022, now offers only limited services in the country.