According to a report in Nextgov, one of the company's lawyers, Scott Christensen, argued that Kaspersky Lab had been singled out for the ban – known as a bill of attainder.
Christensen's other argument was that the ban had taken a financial and reputation toll on Kaspersky that was not in proportion to any security benefit obtained by the US Government.
Kaspersky lost two cases to challenge the ban in May. As iTWire reported, Judge Colleen Kollar-Kotelly, the US District Judge for the District of Columbia, dismissed both suits brought by the company.
And in February this year, the company filed a case against a ban by Congress, codified in the National Defence Authorisation Act for the fiscal year 2018, claiming that the ban was unconstitutional.
Justice Kollar-Kotelly said Kaspersky had failed to prove in court that the NDAA was a bill of attainder; such a bill was defined as "a law that legislatively determines guilt and inflicts punishment upon an identifiable individual without provision of the protections of a judicial trial".
On Friday, Judge David Tatel responded to Christensen's plea to lift the ban, by saying that Congress' aim in putting the stricture in place was “attempting to protect the security of US computer systems,” rather than imposing any punishment on Kaspersky Lab.
Another of the judges, Judge Harry Edwards, disagreed with Christensen's claim that the ban had taken a financial and reputation toll on Kaspersky that was not in proportion to any security benefit obtained by the US Government.
“You [say] the magnitude of the imbalance is significant … Given our concern about Russian intrusion into our national affairs, I don’t see an imbalance,” Justice Edwards said. “Given real-world circumstances, that doesn’t seem so to me at all.”
Christensen also argued that the ban had been hastily put in place without the hearings or debates that are normally gone through before this kind of action is taken, indicating that the main objective was to punish Kaspersky.
But the third judge on the panel. Judge Lewis Yellin, disagreed, saying that the Kaspersky issue had figured in a number of Congressional hearings over 2017.
After the hearing concluded for the day, another Kaspersky lawyer, Ryan Fayhee, told the media: “The effect of this ban is completely disconnected with the genuine articulable threat posed by cyber security. To limit it to that one company in a 750-page must-pass bill reveals exactly what this is."
The ban is due to take effect on 1 October.
Asked for the company's take, a Kaspersky Lab spokesperson said: “Today, the US Court of Appeals for the District of Columbia Circuit heard our arguments on the appeal and Kaspersky Lab remains hopeful that in the end the court will find the law unconstitutional after full consideration of the case on the merits.
“Pursuing this appeal is significant, as the law and the subsequent district court’s decision have set a dangerous precedent with far-reaching implications for the global technology community. Labelling any company as a national security threat just because of its origin, does little to address cyber security risks; therefore, alternatives for a global cyber security risk management and mitigation strategy with general applicability to all IT vendors must be considered.
"Furthermore, the world benefits from global cyber security collaboration, and only by working together, can we preserve and secure the Internet as a global good.
“Despite the ongoing litigation, Kaspersky Lab continues to extend its offer for co-operation, collaboration and an open dialogue to concerned parties.
"The company also continues to advance its Global Transparency Initiative, an ongoing commitment to demonstrating the integrity and trustworthiness of its products, through open collaboration with governments and organisations worldwide.”