At least 30,000 US based organizations including small businesses, towns, cities and local governments have been hacked by an unusually aggressive campaign by Chinese hackers. Hackers have exploited four new flaws in Microsoft Exchange Server email and have seeded tools which give attackers total control over the affected systems, which can also be exercised remotely.

On March 2, Microsoft had released emergency security updates to plug four security issues in Exchange Server versions 2013 through 2019 that were being continuously hacked to siphon e-mail communications.

Sources told media that hackers have perhaps seized control of hundreds of thousands of Microsoft Exchange Servers worldwide. White House spokesperson Jennifer Psaki during a press meet said that it was an active threat. She added that everyone running these servers needs to act now to patch them. It is believed that the numbers of victims are quite large.