[…] The connection to the N.S.A. was particularly chilling. Starting last summer, a group calling itself the “Shadow Brokers” began to post software tools that came from the United States government’s stockpile of hacking weapons.
The attacks on Friday appeared to be the first time a cyberweapon developed by the N.S.A., funded by American taxpayers and stolen by an adversary had been unleashed by cybercriminals against patients, hospitals, businesses, governments and ordinary citizens.
Something similar occurred with remnants of the “Stuxnet” worm that the United States and Israel used against Iran’s nuclear program nearly seven years ago. Elements of those tools frequently appear in other, less ambitious attacks.
The United States has never confirmed that the tools posted by the Shadow Brokers belonged to the N.S.A. or other intelligence agencies, but former intelligence officials have said that the tools appeared to come from the N.S.A.’s “Tailored Access Operations” unit, which infiltrates foreign computer networks. (The unit has since been renamed.)