Embattled cyber security firm Kaspersky Lab said Monday that it is asking a federal court to overturn a ban on its products being used by US agencies.

Allegations that Moscow-based Kaspersky, which sold more than $600 million of anti-virus software globally in 2015, knowingly or unknowingly helped Russian intelligence steal top-secret information from the US have effectively killed its business here and hurt its worldwide reputation.

Kaspersky said it has appealed to a US federal court on the grounds the ban it was hit with is unconstitutional because it denied the company a right to due process regarding the validity of the accusation.

Chief executive Eugene Kaspersky contended in a release that his company has "not been provided a fair opportunity in regards to the allegations and no technical evidence has been produced to validate" action taken by the US Department of Homeland Security (DHS).

Last week, a senior DHS official told reporters that Kaspersky Labs did present a case in its defense but that the department did not change its stance.

Kaspersky said last month that malware-infected Microsoft Office software and not its own was to blame for the hacking theft of top-secret US intelligence materials.

Adding tantalizing new details to a cyber-espionage mystery that has rocked the US intelligence community, Kaspersky also said there was a China link to the hack.

Kaspersky confirmed that someone did apparently steal valuable National Security Agency programs from an NSA worker's home computer, as first reported by the Wall Street Journal on October 5.

According to the Journal, the person had top secret files and programs from an NSA hacking unit called the Equation Group on his computer, which was also using Kaspersky software protection.

They believe that Russian spies used the Kaspersky program as a back door to discover and siphon off the files, reportedly causing deep damage to the NSA's own cyber-espionage operations.

Kaspersky claimed, however, that the computer was infected by other malware, including a Russian-made "backdoor tool" hidden in Microsoft Office.

Kaspersky said that the malware was controlled from a computer server base in Hunan, China, and would have opened a path into the computer for anyone targeting an NSA worker.

Source: AFP