BOSTON (AP) — The sprawling hacking campaign came to be known as SolarWinds, for the company whose software update was seeded by Russian intelligence agents with malware to penetrate government and private networks. Yet it was Microsoft whose code the cyber spies persistently abused in the campaign’s second stage as they rifled through emails and vital files of high-value targets and hopped undetected among victim networks. And that has put the world’s third-most valuable company in the hot seat. Lawmakers are insisting that Microsoft swiftly upgrade security to what they believe it should have provided in the first place, and do it without fleecing taxpayers.