During a U.S. Senate Select Committee on Intelligence, Microsoft Corp’s president Brad Smith stated, the company has notified 60 customers that their data was most likely compromised by hackers during a hacking campaign revolving around Texas-based software firm SolarWinds Corp.

In prepared remarks, Smith told members of the U.S. Senate Select Committee on Intelligence that Microsoft believed some of the methods used by the hackers to break into target networks are not in the public domain; and that “the attacker may have used up to a dozen different means of getting into victim networks during the past year.”

Earlier this month, a top U.S. cyber official had said 9 federal agencies and 100 private-sector companies have been affected by the SolarWind hack, which first came to light in December 2020.

Smith also mentioned, that several other organizations, including unidentified foreign government agencies, have also been breached.