As President Biden announced new sanctions against Russia after its invasion of Ukraine, national security experts expressed concerns about retaliatory cyberattacks on the U.S. and its allies, as well as targeted cyberattacks on Ukraine so forceful they spill beyond the nation’s borders, reports the Washington Post. Such attacks, if aggressive and widespread, could test NATO, creating new debates about when a cyberattack would draw a member nation and its allies into conflict, said Sen. Mark Warner (D-VA), chair of the Senate Intelligence Committee. The Russian government might pursue several different lines of cyberattacks, including targeting the “weaker links in NATO,” in retaliation for Western sanctions, Warner said. He expressed concern that Russian cyber criminals could be unleashed on the West — a tactic that could give the Kremlin plausible deniability for attacks carrying economic consequences for the U.S. and its allies. “It’s a good way to give us the finger without creating a bigger strategic problem for the Russians,” said Jim Lewis of the Center for Strategic and International Studies. Russia is among the countries that have put the most resources behind developing and using formidable hacking tools against rival nations. On Wednesday, cyberattacks disrupted the websites of several Ukrainian government agencies, according to Ukrainian officials, and last week the White House attributed attacks on government sites and banks to the Russian military spy agency GRU. Security researchers identified an unknown strain of malicious software, which began destroying data. have not yet had major ramifications outside of Ukrainian borders. The destructive software deployed during the Russian attacks in Ukraine was also found in Lithuania and Latvia, but only at organizations with a major Ukraine presence. The Symantec security division of Broadcom said Thursday that the malware was aimed at financial, defense, aviation and tech services industries. In some cases, it came camouflaged as ordinary ransomware seeking a payoff.