Updated! Microsoft and several other cloud-based services experienced outages and limited operations early Tuesday afternoon, according to downdetector.com.
Early indicators are that in at least one case this was not a Mirai-like attack, but was possibly associated with a recent software deployment. Sophos Labs told SC Media that it is not seeing this as an attack, while Malwarebytes Senior Security Researcher Jerome Segura confirmed to SC Media that while he too was seeing outages, the cause remained unknown at this time.
Starting around 1 p.m. ET, Microsoft's Outlook.com, Azure, Office 365, Xbox Live and Skype were among the services where outages had been reported. According to downdetector.com, Hootsuite and Charter Spectrum also had outages reported during the same time period, but it is not known at this time if there is a connection.
A Microsoft spokesperson told SC Media, “We're aware that some users are having difficulties logging in to some services. Our engineers are working to fully resolve this as soon as possible.”
Microsoft Azure status history cited a recent deployment as one potential root cause, adding that its engineers rolled back the deployment to help mitigate the issue.
Starting at around 2 p.m. ET, the company's Xbox Live Twitter feed began running comments about the outage saying Microsoft was aware that its Xbox Live users could not sign in and were actively working on the issue. By 4 p.m. ET, Xbox Live said some progress had been made, but no mention was made of what caused the outage.
We're aware of reports of trouble logging into Xbox Live. We're working hard to get things resolved. Stay tuned to: https://t.co/99xfLMWcZW
— Xbox Support (@XboxSupport) March 21, 2017
Xbox Live suffered a similar outage during the evening of March 19.
No comments were made on the Twitter feeds of any of the other products.
In late October, the Mirai botnet was used to attack Dyn DNS with a massive DDoS attack that took down Twitter, Spotify, Netflix, GitHub, Amazon, Reddit and other websites.
Update includes Microsoft's response to the situation.
