Technical experts have spent the past day or so picking apart a suite of tools allegedly stolen from the Equation Group , a powerful squad of hackers which some have tied to the NSA. The tools materialized as part of an internet electronic auction set up by a group calling itself "Shadow Brokers," which has promised to leak more data to whoever puts in a winning bid.

In a series of messages posted to Twitter , Snowden suggested the leak was the fruit of a Russian attack on an NSA-controlled server and could be aimed at heading off U.S. retaliation over allegations that the Kremlin is interfering in the U.S. electoral process.