The US National Security Agency (NSA) has denied it operated a botnet of hijacked computers in order to spy on people.
"Recent media reports that allege NSA has infected millions of computers around the world with malware, and that NSA is impersonating U.S. social media or other websites, are inaccurate," the NSA said in a statement.
"NSA uses its technical capabilities only to support lawful and appropriate foreign intelligence operations, all of which must be carried out in strict accordance with its authorities. Technical capability must be understood within the legal, policy, and operational context within which the capability must be employed."
The denial follows leaks made by whistleblower Edward Snowden, which suggest the NSA operated a system called QUANTUMBOT, which searched for compromised networks and took over their command and control centres. These would then allegedly be used to install malware.
The agency was also accused of operating a fake Facebook server to install malware and steal documents from users' computers. NSA news outlet The Intercept cited leaked documents from Snowden for these allegations.
The NSA reiterated that it "does not use its technical capabilities to impersonate U.S. company websites" or "target any user of global Internet services without appropriate legal authority." It labelled the allegations as "simply false."