Suspected Russian hackers used Microsoft vendors to breach customers

FILE PHOTO: The logo of Microsoft is seen at an office building in Wallisellen, Switzerland December 21, 2020. REUTERS/Arnd Wiegmann/File photo

WASHINGTON (Reuters) - The suspected Russian hackers behind the worst U.S. cyber attack in years leveraged reseller access to Microsoft Corp services to penetrate targets that had no compromised network software from SolarWinds Corp, investigators said.

While updates to SolarWinds' Orion software was previously the only known point of entry, security company CrowdStrike Holdings Inc said Thursday hackers had won access to the vendor that sold it Office licenses and used that to try to read CrowdStrike's email.