The private Gmail account of a top US intelligence official has reportedly been hacked by an unknown cybercriminal going by the pseudonym Jonnie Walker. The hacker sent out a mass email to an unknown number of recipients claiming to possess a trove of confidential emails from the private email account of a senior US State Department official, whose work allegedly focuses on Russia, Foreign Policy reported.

Reports of the hack come even as the US government continues to conduct several separate investigations into Russia's reported efforts to infiltrate and influence last year's election. Meanwhile, the White House continues to dodge allegations of the Trump campaign's collusion with Russia during the 2016 presidential election.

No confirmation or denial from State Department

The authenticity of the emails leaked by the hacker was neither confirmed nor denied by the US State Department. "The Department of State is well aware that malicious actors often target email accounts of government and business leaders across the United States. As a matter of policy, we do not discuss specific attempts or incidents," a spokesperson for the State Department said.

Although the identity of the target has not been disclosed due to security reasons, Foreign Policy reported that the intelligence official, whose account was hacked, works for the State Department's Bureau of Intelligence and Research. "He's probably the top intelligence guy in the entire US government on Russia. He knows more than anybody about what's going on there," said one unnamed source, who allegedly corresponded with the official, the cyberattack reportedly revealed.

The hacker's mass email included correspondence between the Russia expert and "CIA officers and other intelligence agencies, mainstream media, NGOs, and international funds" that would "give you evidence of who is responsible for agenda formation in many countries worldwide, especially where the situation is insecure".

Other Russia experts also hacked

Foreign Policy reported that another source, whose correspondence appeared in the hacked emails, said at least one other Russia expert – an Australian academic with a history of government work - was also recently hacked. "The Kremlin's standard line is that its opponents are pawns of foreign intelligence services," the source said.

Although there is no evidence yet to suggest that the attack was the work of Russian hackers, according to US intelligence officials, this may be a possibility. "The Russians are probably the most aggressive intelligence service in the world," John Sipher, a 38-year veteran of the CIA's National Clandestine Service, told Foreign Policy. "The fact that they did go after State Department officials is completely consistent with the way the Russians behave."

"Clearly Russia would be interested in hacking a Russia expert," said Jon Nichols, a cyber-information operations expert. "But any kid would also be interested in hacking a Russia expert for the optics of it."