Krebs: US should be 'cautious' about escalating cyber war with Russia

Former Cybersecurity and Infrastructure Security Agency (CISA) chief Christopher Krebs in an interview on Sunday poured cold water on lawmakers' calls for retaliation in response to a cyber intrusion at numerous government agencies believed to be carried out by Russia.

Speaking with CNN's Jake TapperJacob (Jake) Paul TapperFrederica Wilson rails against Haitian deportation flights, calls treatment 'inhumane' WHIP LIST: How House Democrats say they'll vote on infrastructure bill Yarmuth and Clyburn suggest .5T package may be slimmed MORE on "State of the Union," Krebs said that lawmakers such as Sen. Mitt RomneyWillard (Mitt) Mitt RomneyGraham tries to help Trump and McConnell bury the hatchet GOP senator will 'probably' vote for debt limit increase Five questions and answers about the debt ceiling fight MORE (R-Utah,) who called for "a cyber response of like magnitude or greater" earlier on the program, should be "cautious." 

“I’d be very careful with escalating this," Krebs responded.

"We need a conversation among like-minded countries" about what are acceptable forms of cyber espionage, the former U.S. cybersecurity chief added.

Krebs was also asked during the interview about tweets on Saturday from President TrumpDonald TrumpJulian Castro knocks Biden administration over refugee policy Overnight Energy & Environment — League of Conservation Voters — Climate summit chief says US needs to 'show progress' on environment Five takeaways from Arizona's audit results MORE, who contradicted top U.S. officials and suggested China's involvement in both the cyberattack as well as unfounded allegations of intrusions into U.S. voting systems.

“It’s Russia," Krebs responded on Sunday, before adding of Russia's intelligence service, the SVR: "They are exceptionally good at it.”

The hack was possible, he added, because outdated systems are still being used across government agencies that have not upgraded their capabilities in years and were not "optimized" to be defended easily.

Krebs was fired last month by the president after the former CISA leader declared that the 2020 election had been free of foreign influence and the most secure in U.S. history, contradicting the president's own evidence-free claims of widespread voter fraud and corruption.

The president has remained largely focused on his so far unsuccessful efforts to overturn his election defeat, and has only commented a handful of times on other issues in recent days.