Federal authorities expressed increased alarm on Thursday (US time) about a long-undetected intrusion into US and other computer systems around the globe that officials suspect was carried out by Russian hackers. The nation's cybersecurity agency warned of a "grave" risk to government and private networks.
The hack compromised federal agencies and "critical infrastructure" in a sophisticated attack that was hard to detect and would be difficult to undo, the Cybersecurity and Infrastructure Security Agency said in an unusual warning message. The Department of Energy acknowledged it was among those that had been hacked.
The attack, if authorities can prove it was carried out by Russia as experts believe, creates a fresh foreign policy problem for President Donald Trump in his final days in office.
Trump, whose administration has been criticised for eliminating a White House cybersecurity adviser and downplaying Russian interference in the 2016 presidential election, has made no public statements about the breach.
President-elect Joe Biden, who will inherit the potentially difficult US-Russia relationship, spoke up forcefully about the hack, declaring that he and Vice President-elect Kamala Harris "will make dealing with this breach a top priority from the moment we take office".
"We need to disrupt and deter our adversaries from undertaking significant cyberattacks in the first place," he said. "We will do that by, among other things, imposing substantial costs on those responsible for such malicious attacks, including in coordination with our allies and partners."
"There's a lot we don't yet know, but what we do know is a matter of great concern," he said. He thanked administration "public servants" who he said were "working around-the-clock to respond to this attack".
CISA officials did not respond to questions and so it was unclear what the agency meant by a "grave threat" or by "critical infrastructure" possibly targeted in the attack that the agency previously said appeared to have begun last March. Homeland Security, the agency's parent department, defines such infrastructure as any "vital" assets to the US or its economy, a broad category that could include power plants and financial institutions.
The agency previously said the perpetrators had used network management software from Texas-based SolarWinds to infiltrate computer networks. Its new alert said the attackers may have used other methods, as well.
Over the weekend, amid reports that the Treasury and Commerce departments were breached, CISA directed all civilian agencies of the federal government to remove SolarWinds from their servers. The cybersecurity agencies of Britain and Ireland issued similar alerts.
A US official previously told The Associated Press that Russia-based hackers were suspected, but neither CISA nor the FBI has publicly said who is believed to be responsible. Asked whether Russia was behind the attack, the official said: "We believe so. We haven't said that publicly yet because it isn't 100 per cent confirmed."
Another US official, speaking on Thursday on condition of anonymity to discuss a matter that is under investigation, said the hack was severe and extremely damaging although the administration was not yet ready to publicly blame anyone for it.
"This is looking like it's the worst hacking case in the history of America," the official said. "They got into everything."
At the Department of Energy, the initial investigation revealed that malware injected into its networks via a SolarWinds update has been found only on its business networks and has not affected national security operations, including the agency that manages the nation's nuclear weapons stockpile, according to its statement. It said vulnerable software was disconnected from the DOE network to reduce any risk.
The intentions of the perpetrators appear to be espionage and gathering information rather than destruction, according to security experts and former government officials. If so, they are now remarkably well situated.
Thomas Bossert, a former Trump Homeland Security adviser, said in an opinion article in The New York Times that the US should now act as if the Russian government had gained control of the networks it has penetrated. "The actual and perceived control of so many important networks could easily be used to undermine public and consumer trust in data, written communications and services," he wrote.
Members of Congress said they feared that taxpayers' personal information could have been exposed because the IRS is part of Treasury, which used SolarWinds software.
Tom Kellermann, cybersecurity strategy chief of the software company VMware, said the hackers are now "omniscient to the operations" of federal agencies they've infiltrated "and there is viable concern that they might leverage destructive attacks within these agencies" in reaction to US response.
Among the business sectors scrambling to protect their systems and assess potential theft of information are defence contractors, technology companies and providers of telecommunications and the electric grid.