It was announced last week that hackers had breached the software vendor SolarWinds, which works with multiple US government agencies, and had disguised the hack through software updates.
On Friday, US secretary of state Mike Pompeo confirmed that he believes Russia was behind the hack that breached at least a dozen federal agencies over a nine month period.
Speaking on the Mark Levin Show on Friday evening, Mr Pompeo said that the hack is “pretty clearly” linked to Russia, but told the host: “I can’t say much more as we’re still unpacking precisely what it is, and I’m sure some of it will remain classified.”
He added: “This was a very significant effort, and I think it’s the case that now we can say pretty clearly that it was the Russians that engaged in this activity.”
Former and current US officials called for the US to retaliate, but stopped short of blaming Russia for the attack.
The methods used to carry out the cyberhack are consistent with Russian cyber operations.
But it’s crucial we have complete certainty about who is behind this.
We can’t afford to be wrong on attribution, because America must retaliate, and not just with sanctions.
— Marco Rubio (@marcorubio) December 18, 2020
Senator Marco Rubio, who leads the Senate Intelligence Committee, tweeted on Friday that “the methods used to carry out the cyber attack are consistent with Russian cyber operations, but it’s crucial we have complete certainty about who is behind this.”
He added: “We can’t afford to be wrong on attribution, because America must retaliate, and not just with sanctions.”
Mr Rubio, who is a Florida senator and previously ran for the Republican nomination for president, told Fox News on Thursday that the attack is close to an act of war.
“You saw the bulletin tonight, it went out, it’s a grave risk to federal, to state, to local governments, to critical infrastructure, to the private sector,” Mr Rubio said.
“And as far as attribution, when you attribute it to somebody, you have got to know it for sure because it’s a very — this is almost, I would argue — an act of war, absolutely,” he added.
While on Friday, the Trump administration’s former national security adviser John Bolton told MSNBC that the hack is “much more serious than just Russia.”
However, he added that “the top priority has got to be, if we determine it is the Russians – that’s where the information tends to point – what the retaliation is going to be.
“I think it ought to be whatever we assess the cost we have incurred to be, plus, plus, plus. That’s how you re-establish deterrence.”
President Trump has still not commented on the attack, despite the House of Representatives being briefed on it on Friday, according to the Miami Herald.
When asked by Mr Levin on Friday if President Trump would comment on the attack, Mr Pompeo said that sometimes the “wiser course of action to protect the American people is to calmly go about your business and defend freedom.”
The FBI’s Cyber Division is investigating the security breach. The agency said earlier in the week that its preliminary findings suggest that the hack was carried out with “a high level of sophistication consistent with a nation-state.”