The level of a sophistication of the most recent cyberattack on the United States suspected to be a Russian hack that the government unearthed this week is much larger than first expected. 

Russian Hack is 'Grave Threat'

According to the Cybersecurity and Infrastructure Security Agency on Thursday, the cyberattack poses a severe risk to the federal government.

Federal authorities raised an increased alarm on Thursday about the long-undetected cyber interference into the US and other computer systems across the globe that officials alleged was initiated by hackers from Russia. The country's cybersecurity agency also cautioned of a "grave" risk to private networks.

Lawmakers are posing questions regarding whether the attack against the federal government widely attributed to Russia represents an act of war, reported The Hill.

The hacking may constitute the largest cyberattack in the nation's history, and officials are grappling to respond.

The more information gathered regarding the recent hack into dozens of America's most crucial computer networks, the more it becomes clear that the hacking is unprecedented, massive, and crippling. According to Tom Bossert, who served as homeland security adviser to President Donald Trump, "It will take years to know for certain which networks the Russians control and which ones they just occupy," reported Washington Post.

The Cybersecurity and Infrastructure and Security Agency added that state, local, tribal, and territorial governments, along with critical infrastructure entities and other private sector organizations, are susceptible to the threat.

CISA believes the attack culminated in March. Since then, a number of government agencies have reportedly been targeted by the alleged Russian hackers. The Energy and Commerce departments confirmed this so far.

Also Read: Russia Suspected Behind SolarWinds Hack, US Cybersecurity Agency Issues Emergency Directive

The hack manipulated federal agencies and "critical infrastructure" in a refined attack that was not easily detected and will be difficult to undo, according to the CISA, in an unusual warning message.

The cyberattack, if authorities could prove it was carried out by Russians, as experts think, develops a new foreign policy problem for President Trump.

Trump has not yet commented publicly on the attack, and the US has yet to come up with a clear cyber warfare strategy.

"We can't be buddies with Vladimir Putin and have him at the same time making this kind of cyberattack on America." This is deemed as a signal of war by Russia on the United States, which should be taken seriously, according to Senate Minority Whip Dick Durbin (D-Ill.) regarding the attack during an interview.

On Thursday, Sen. Mitt Romney (R-Utah) compared the scenario to Russian bombers flying undetected across the nation.

Russia has remarkably upgraded its hybrid warfare, using new strategies to spread chaos among its opponents.

According to the CISA, "This threat actor has demonstrated sophistication and complex tradecraft in these intrusions." The agency added removing the threat actor from manipulated environments will be largely complicated and challenging, reported CNBC.

CISA officials declined to respond to questions, so it was not made clear what the agency meant by a "grave threat" or by "critical infrastructure" possibly targeted.

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