Facebook and Microsoft acted last week to disable a number of North Korean cyber actions, White House homeland security adviser Tom Bossert said on Tuesday as the United States publicly blamed Pyongyang for a May cyber attack that crippled hospitals, banks and other companies.

Bossert did not provide details on those actions but said the U.S. government was calling on companies to cooperate in cyber security defense.

Source: Tech CNBC
Facebook and Microsoft independently stopped North Korean cyberattacks last week, a US official says