Cybersecurity

Hackers Rushed in as Microsoft Raced to Avert Cyber-Attack

  • U.S. president briefed as crisis around Exchange bugs mounts
  • Company investigates possible leak during patching process

Photographer: Drew Angerer/Getty Images

Lock
This article is for subscribers only.

It was late February, and Microsoft Corp. engineers had been working for weeks on a handful of alarming weaknesses in the company’s popular Exchange email service. They were rushing to send out a fix, targeting the second Tuesday of March -- part of a monthly ritual known in cybersecurity circles as “patch Tuesday.”

The hackers got a head start. Following weeks of discreet attacks, Chinese hackers shifted into high gear. The result was a sprawling campaign that engulfed thousands of organizations in a matter of days.