Microsoft says 'no evidence of malicious activity' as Outlook and Teams claw back from a nearly day-long global outage

Microsoft said Friday morning it has found "no evidence of malicious activity" behind the worldwide disruption that knocked out Outlook email, Teams, OneDrive and other Office 365 apps for companies, governments and schools since midday Thursday, the Washington Examiner reports.

"At this time, we have no evidence of malicious activity associated with this incident," the company said at 6:11 a.m. ET. "We will continue to treat this with urgency until full mitigation, and we will share a full Post-Incident Report with root cause and defense-in-depth actions after mitigation is complete."

Microsoft has been fighting the problem since around midday Thursday. At one point it said its efforts to restore its infrastructure were not taking as expected and were not "resulting in sustained recovery." Early Friday it said it was "seeing encouraging recovery progress," while warning that users may still run into intermittent issues.

At the peak Thursday, more than 130,000 Outlook users reported problems, according to Downdetector, which logged about 15,000 reports around 6 a.m. Friday. The disruption hit Microsoft apps in at least 74 countries within an hour on Thursday.

The effects reached well beyond inboxes. Colorado's Arapahoe County Sheriff's Office said it could not process online bond payments while Outlook was down, and the Supreme Court of the Philippines said its legal work was delayed.

Charles Lamanna, a Microsoft executive vice president, said overnight there was no indication the outage was "the result of malicious or cyber activity." Microsoft has not yet said what caused it.