Microsoft has shared some information about an outage that impacted its services earlier this month.
The disruption affected the computer giant’s Azure cloud computing platform, along with Microsoft tools such as the Outlook email and OneDrive file-sharing apps.
At the time, Microsoft said little about the incident, but in a post published over the weekend, it confirmed the cause to be distributed denial-of-service (DDoS) attacks, a malicious act that attempts to disrupt a server or network by overwhelming it with incoming internet traffic.
With Microsoft offering a large number of cloud-based services, the attack could potentially have impacted millions of its customers around the world, though the company has yet to reveal the precise extent of the disruption.
Following the outage, Microsoft said it began tracking activity by the threat actor, which it named Storm-1359 using a naming convention that it deploys for groups while investigations are underway. It added that the perpetrator “appears to be focused on disruption and publicity.”
At the time, a hacking group called Anonymous Sudan claimed responsibility for the attack, and in recent days Microsoft confirmed to the Associated Press (AP) that it believes this to be the case.
The company said that after investigating the incident, it had “seen no evidence that customer data has been accessed or compromised,” but advised customers to review the technical details and recommendations listed in its post in order to increase the resilience of their systems to help mitigate similar attacks.
Anonymous Sudan emerged at the beginning of this year and claims to target nations that interfere in Sudanese politics or promote anti-Muslim views, according to Bleeping Computer. But some security researchers believe that the group may have links to the pro-Kremlin Killnet hacker group, raising the possibility that the standpoint on Sudan may be a decoy.
While further details about the incident may yet come out, perhaps most alarming for Microsoft is that it was unable to effectively deal with a DDoS attack, a common form of attack that enables malicious actors to impact the availability of online services.