BOSTON (AP) — The state-backed Russian cyber spies behind the SolarWinds hacking campaign launched a targeted spear-phishing assault on U.S. and foreign government agencies and think tanks this week using an email marketing account of the U.S. Agency for International Development, Microsoft says.

The effort targeted about 3,000 email accounts at more than 150 different organizations, at least a quarter of them involved in international development, humanitarian and human rights work, Microsoft Vice President Tom Burt said in a blog post late Thursday.

It did not say what portion of the attempt...