London Daily

Focus on the big picture.
Saturday, Jul 05, 2025

Microsoft hack: White House warns of 'active threat' of email attack

Microsoft hack: White House warns of 'active threat' of email attack

The US is expressing growing concern over a hack on Microsoft's Exchange email software that the tech company has blamed on China.

"This is an active threat," White House press secretary Jen Psaki said on Friday. "Everyone running these servers - government, private sector, academia - needs to act now to patch them."

Microsoft said hackers had used its mail server to attack their targets.

It is reported that tens of thousands of US organisations may be impacted.

The US has long accused the Chinese government of cyber-espionage, something Beijing denies.

Ms Psaki told reporters that the White House was "concerned that there are a large number of victims" and said the vulnerabilities found in Microsoft's servers "could have far reaching impacts".

On Saturday, the US National Security Council said it was "essential that any organisation with a vulnerable server take immediate measures" to determine if they had been targeted.


What do we know about the hack?


Microsoft executive Tom Burt revealed the breach in a blog post on Tuesday and announced updates to counter security flaws which he said had allowed hackers to gain access to Microsoft Exchange servers.

The Microsoft Threat Intelligence Center (MSTIC) attributed the attacks with "high confidence" to a "state-sponsored threat actor" based in China which they named Hafnium.

The tech giant said Hafnium had tried to steal information from groups such as infectious disease researchers, law firms, higher education institutions and defence contractors.

A spokesman for the Chinese government told Reuters news agency that the country was not behind the hack. Beijing has repeatedly rejected US accusations of cyber-crime.

More than 20,000 organisations have been compromised in the US with many more affected worldwide, Reuters reported.

Brian Krebs, an industry expert and blogger, put the number higher - citing multiple security sources.

"At least 30,000 organizations across the United States - including a significant number of small businesses, towns, cities and local governments - have over the past few days been hacked by an unusually aggressive Chinese cyber-espionage unit that's focused on stealing email from victim organizations," he wrote in a blog post.

Mr Krebs warned attacks had "dramatically stepped up" since Microsoft's announcement.

What is Microsoft doing?


News of the breach prompted the US Cybersecurity and Infrastructure Security Agency (Cisa) to release an emergency directive telling agencies and departments to take urgent action.

Jake Sullivan, the White House National Security Adviser, has also urged network owners to download the security patches as soon as possible.


Microsoft has not confirmed the reported figures but said in a further statement on Friday that it was working closely with US government agencies.

It told customers "the best protection" was "to apply updates as soon as possible across all impacted systems".

However, it also said it was deploying some mitigation techniques designed to help those who are unable to upgrade quickly, but warned they were not "a remediation if your Exchange servers have already been compromised, nor are they full protection against attack".

This is the eighth time in the past 12 months that Microsoft has publicly accused nation-state groups of targeting institutions critical to civil society.

Microsoft said the attack was in no way related to the SolarWinds attack, which hit US government agencies late last year.

Although Hafnium is based in China, it allegedly conducts its operations primarily from leased virtual private servers in the US, Microsoft said.

China presence


While many US tech firms have had a tumultuous relationship with the Chinese government, Microsoft has maintained a mainland presence since 1992.

Unlike Facebook and Twitter, Microsoft's business-oriented social media platform LinkedIn is still accessible in China.

So, too, is its search engine Bing, although locally-grown Baidu dominates the search market.

Newsletter

Related Articles

0:00
0:00
Close
Elon Musk Founds a Party Following a Poll on X: "You Wanted It – You Got It!"
London Stock Exchange Faces Historic Low in Initial Public Offerings
A new online platform has emerged in the United Kingdom, specifically targeting Muslim men seeking virgin brides
Trump Celebrates Independence Day with B-2 Flyover and Signs Controversial Legislation
Boris Johnson Urges Conservatives to Ignore Farage
SNP Ordered to Update Single-Sex Space Guidance Within Days
Starmer Set to Reject Calls for Wealth Taxes
Stolen Century-Old Rolls-Royce Recovered After Hotel Theft
Macron Presses Starmer to Recognise Palestinian State
Labour Delayed Palestine Action Ban Over Riot Concerns
Swinney’s Tax Comments ‘Offensive to Scots’, Say Tories
High Street Retailers to Enforce Bans on Serial Shoplifters
Music Banned by Henry VIII to Be Performed After 500 Years
Steve Coogan Says Working Class Is Being ‘Ethnically Cleansed’
Home Office Admits Uncertainty Over Visa Overstayer Numbers
JD Vance Questions Mandelson Over Reform Party’s Rising Popularity
Macron to Receive Windsor Carriage Ride in Royal Gesture
Labour Accused of ‘Hammering’ Scots During First Year in Power
BBC Head of Music Stood Down Amid Bob Vylan Controversy
Corbyn Eyes Hard-Left Challenge to Starmer’s Leadership
London Tube Trains Suspended After Major Fire Erupts Nearby
Richard Kemp: I Felt Safer in Israel Under Attack Than in the UK
Cyclist Says Police Cited Human Rights Act for Riding No-Handed
China’s Central Bank Consults European Peers on Low-Rate Strategies
AI Raises Alarms Over Long-Term Job Security
Saudi Arabia Maintains Ties with Iran Despite Israel Conflict
Musk Battles to Protect Tesla Amid Trump Policy Threats
Air France-KLM Acquires Majority Stake in Scandinavian Airlines
UK Educators Sound Alarm on Declining Child Literacy
Shein Fined €40 Million in France Over Misleading Discounts
Brazil’s Lula Visits Kirchner During Argentina House Arrest
Trump Scores Legislative Win as House Passes Tax Reform Bill
Keir Starmer Faces Criticism After Rocky First Year in Power
DJI Launches Heavy-Duty Coaxial Quadcopter with 80 kg Lift Capacity
U.S. Senate Approves Major Legislation Dubbed the 'Big Beautiful Bill'
Largest Healthcare Fraud Takedown in U.S. History Announced by DOJ
Poland Implements Border Checks Amid Growing Migration Tensions
Political Dispute Escalates Between Trump and Musk
Emirates Airline Expands Market Share with New $20 Million Campaign
Amazon Reaches Milestone with Deployment of One Millionth Robot
US Senate Votes to Remove AI Regulation Moratorium from Domestic Policy Bill
Yulia Putintseva Calls for Spectator Ejection at Wimbledon Over Safety Concerns
Jury Deliberations in Diddy Trial Yield Partial Verdict in Serious Criminal Charges
House Oversight Committee Subpoenas Former Jill Biden Aide Amid Investigation into Alleged Concealment of President Biden's Cognitive Health
King Charles Plans Significant Role for Prince Harry in Coronation
Two Chinese Nationals Arrested for Espionage Activities Against U.S. Navy
Amazon Reaches Major Automation Milestone with Over One Million Robots
Extreme Heat Wave Sweeps Across Europe, Hitting Record Temperatures
Meta Announces Formation of Ambitious AI Unit, Meta Superintelligence Labs
Robots Compete in Football Tournament in China Amid Injuries
×