Russian Hackers Breached Defense Firms Over Two Years, U.S. Says

U.S. officials said Wednesday that Russian state-backed hackers have been targeting U.S. defense contractors for the last two years, acquiring “sensitive” information, including about weapons development.

The hackers have used “common but effective tactics,” including the harvesting of user credentials and spearphishing attacks, to gain access to large and small defense contractors, according to a statement from the National Security Agency, the Federal Bureau of Investigation and the Department of Homeland Security’s Cybersecurity and Infrastructure Security Agency.

The hackers have managed to maintain access to the companies, sometimes for as long as six months, by using legitimate credentials as well ...