President Barack Obama’s administration has officially blamed Russia for the recent hacks to influence the 2016 presidential election. Fingers have longed pointed fingers at Russia whenever hackers posted emails from the Democratic National Committee and phone calls with Democrats, but now U.S. intelligence agencies have enough confidence to put the blame on Russia:

“We believe, based on the scope and sensitivity of these efforts, that only Russia’s senior-most officials could have authorized these activities,” the statement said.

The agencies said some state election systems have been recently scanned and probed and that this action originated from servers operated by a Russian company. But the statement stopped short of definitively blaming the Russian government for that activity.

Just days before the Democrat National Committee, a Romanian hacker known as Guccifer 2.0 gave emails to Wikileaks that showed the DNC conspired from within to ruin Sen. Bernie Sanders (I-VT) campaign against Hillary Clinton.

This caused the DNC to “quarantine” then-DNC Chairwoman Rep. Debbie Wasserman Schultz from the Democrat convention. She later resigned a day before the convention kicked off while the DNC fired three top officials.

Another document dump showed emails that contained the words pay to play. Those high paying donors eventually became ambassadors. Other emails showed the DNC staged TV protests.

U.S. officials have now said all of these hacks come from Russia:

“The U.S. Intelligence Community is confident that the Russian Government directed the recent compromises of emails from U.S. persons and institutions, including from U.S. political organizations,” said the joint statement from agencies including the Central Intelligence Agency and the National Security Agency.

It added that leaks by three entities—a hacker self-described as Guccifer 2.0, the website DCleaks.com and the organization WikiLeaks—“are consistent with the methods and motivations of Russian-directed efforts. These thefts and disclosures are intended to interfere with the U.S. election process.”

Also, just last week, a Department of Homeland Security official said hackers targeted election systems in 21 states. This has led DHS to persuade states to take advantage of federal and private protection of its election systems.

Concerns over election security peaked in August when “hackers successfully infiltrated one state board of election and targeted another” in Illinois and Arizona.

The FBI provided “eight separate IP addresses” and thinks they may have been linked since the hackers used one address in bothe attacks. The department recognized one address since it “surfaced before in Russian criminal underground hacker forums.” Rich Barger, chief intelligence officer for cybersecurity firm ThreatConnect, told Yahoo News that “the method of attack on one of the state election systems — including the types of tools used by the hackers to scan for vulnerabilities and exploit them — appears to resemble methods used in other suspected Russian state-sponsored cyberattacks, including one just this month on the World Anti-Doping Agency.”

The Kremlin, of course, has denied the accusations.

The Wall Street Journal provided the options the administration may use against Russia:

An administration official said the U.S. government could activate numerous measures in response to the alleged Russian operation, including diplomatic and economic steps as well as criminal charges.

Accusing a foreign government of attempting to interfere in the U.S. election leaves several difficult choices for the White House. Many computer experts and even U.S. lawmakers have said there should be more of a deterrent to prevent nation states from launching computer attacks.

The White House may choose to level sanctions against Russia or Russian businesses believed connected to the operation, or it may launch computer attacks of its own if President Barack Obama believes such retaliation is merited.

Democrats and Republicans in Congress grew frustrated with the administration for not calling out Russia. California Democrats Adam Schiff and Dianne Feinstein, the top Democrats on the House and and Senate intelligence committees, cited classified briefings weeks ago that proved Russia did commit the hackings. Schiff praised the announcement:

“I hope this will establish a deterrent to further meddling,” he said. “I don’t think the Russians have decided yet how much they plan to continue their interference, so I think this attribution is very timely. We’re also encouraging the administration to work with our European partners, who have been the subject of even worse meddling, to coordinate a response to this.”