Microsoft is back in the firing line after US Senator Ron Wyden accused Redmond of shipping "dangerous, insecure software" that helped cybercrooks cripple one of America's largest hospital networks.

Microsoft rewarded for security failures with another US government contract

Wyden's letter [PDF], delivered to FTC chair Andrew Ferguson on September 10, paints Microsoft not just as a careless vendor, but as a danger to national security.

"I urge the FTC to investigate Microsoft and hold the company responsible for the serious harm it has caused by delivering dangerous, insecure software to the US government and to critical infrastructure entities, such as those in the US healthcare sector," Wyden wrote.

"Without timely action, Microsoft's culture of negligent cybersecurity, combined with

See Full Page