The publication, which in the wake of Glenn Greenwald's departure from The Guardian continued to publish documents leaked by Edward Snowden, said on Monday the recently discovered malware, known as Regin, was used against targets in the European Union.
One of those targets included Belgian telecommunications company Belgacom, which had its networks broken into by the British spy agency the Government Communications Headquarters (GCHQ).
Compared to Stuxnet, the state-sponsored malware whose creators have never been confirmed, the recently-discovered trojan steals data from machines and networks it infects, disguised as Microsoft software.
They weren't far off. According to Monday's report, the U.S. working in conjunction with Britain, a European member state (though perhaps not for much longer) attacked Belgacom using the Regin malware.
The new details from The Intercept show how GCHQ embarked upon its "hacking mission," known as Operation Socialist, by accessing Belgacom's networks in 2010. By targeting engineers through a faked LinkedIn page, GCHQ was able to get deep inside the Internet provider to steal data.
One of Belgacom's main clients was the European Commission, the European Parliament, and the European Council of member state leaders.
Exactly how member states of the European Union — there are 28 of them including the U.K. — will react to one of its own member states launching a successful hacking attack against their executive body, remains unknown.