The Federal Election Commission restored its electronic filing system on Wednesday night after taking it offline for nearly 41 hours to contain a cyberattack. The outage left super PACs and other groups unable to file mandatory reports disclosing last-minute spending in the final days before the November 3 midterms, temporarily shielding that spending from public view. Campaign finance watchdogs warned that the blackout struck as outside spending was running at its fastest pace of the cycle, with more than $250 million reported on October 20 alone. The agency has not disclosed the cause or motive, and officials stressed the outage does not affect voters’ ability to cast ballots, since the commission does not administer elections.

Full report: Cyberattack concealed political spending by big donors before US midterm elections.