After the November elections, officials in the Obama administration accused Russian President Vladimir Putin of attacking the US election and imposed sanctions on the nation. Reuters later reported that the FBI was conducting three separate investigations into Russian election hacking that targeted Democrat party workers.

The latest reports from unnamed US officials, however, suggest that things were actually worse than thought. In July of 2016, Illinois election officials discovered a breach in the voter database, which led investigators to IP addresses and other digital signatures. Investigators subsequently discovered similar signs of attacks in 37 other US states.

Hackers attempted and failed to alter Illinois voter databases, something that wasn't known until now. Unnamed officials told Bloomberg they're worried it was just a test run by Russians in preparation for a more aggressive attack. According to an NSA documents obtained by The Intercept (which resulted in the arrest of leaker Reality Leigh Winner), Russia's GRU military intelligence arm tried to take over the computers of 122 local election officials prior to the November vote.

A US voting machine (David Ryder/Reuters)

The DHS told US swing states to protect their voting systems from attacks last year, but officials in states like Georgia brushed aside the advice. After resistance from Republicans, voting machines were declared "critical infrastructure, deterring foreign interference and allowing the DHS to give assistance to state or local officials who request it.

Until recently, Putin has vehemently denied that the Russians were involved in hacking US elections. However, earlier this month Putin acknowledged that Russian hacking into the US election was "theoretically possible," while still insisting the government had no role. The Trump administration hasn't taken the problem seriously enough, according an ex-FBI official.

President Obama reportedly contacted the Kremlin on a new "red phone" communications system established in 2011, the report states. The White House showed the Kremlin proof of the attacks and asked for more information, but the hackers' work continued anyway. In the end, Obama reportedly decided not to reveal the extent of Russian activity, worrying it would shake the public's faith in the election process -- a decision he may regret now.