US Special Counsel Robert Mueller’s office said the attack happened after the investigation of a firm charged with funding a Russian propaganda campaign to interfere in the 2016 US election.
Prosecutors said in a court filing in Washington that a Twitter handle called @HackingRedstone came online last 22 October to brag it had hacked some of the evidence in the case.
“We’ve got access to the Special Counsel Mueller’s probe database as we hacked Russian server with info from the Russian troll case”, the court document quoted the Twitter post as saying.
The companies named in the indictment included the Internet Research Agency (IRA), known for its “trolling” on social media, Concord Management and Consulting, which is said to have provided financial backing for the operation, and Concord Catering.
The Twitter account linked to an online file sharing portal which it said contained Mueller’s documents about the “IRA and Russian collusion”.
The data that appeared online was “altered and disseminated as part of a disinformation campaign aimed (apparently) at discrediting ongoing investigations into Russian interference in the US political system”, prosecutors wrote.
On the same day, a journalist contacted Mueller’s office to report receiving a Twitter message from someone who said they had hacked a Russian legal firm that had received the evidence from Concord’s US based law firm Reed Smith LLP.