Enterprises using Microsoft Teams suffered another period of disruption this week as the platform’s file-sharing capabilities endured an outage.
Many Teams user organisations saw their collaboration experiences undermined by a strange problem that began on Tuesday during US business hours, with people and businesses highlighting various file-sharing issues on X, ranging from downloads no longer working to attachments failing to upload.
Microsoft promptly acknowledged the situation and initiated an investigation. A notification, TM1055900, was published in the Message Center as their engineering team began troubleshooting the issue:
We’re investigating an issue impacting Files sharing functionality within Microsoft Teams. Further details can be found under TM1055900 in the admin center.”
After several hours of analysis, Microsoft pinpointed the root cause: an unexpected modification to the backend infrastructure had triggered the disruption. Reversing the change restored normal operations. In the meantime, a temporary workaround was available, offering some relief to impacted users: they could still access and view previously uploaded files by navigating to the ‘Shared’ tab within all Teams clients.
Microsoft also acknowledged the situation, stating, “We are currently reviewing our change management procedures to determine why this issue was not identified before deployment.”
Teams’ Ongoing Challenges Around Outages and Security
Naturally, high-profile outages are hardly alien to Microsoft. Last summer, the tech giant was at the epicentre of a global IT crisis, which was traced to a faulty update from cybersecurity firm CrowdStrike. Initially, the widespread impact on Microsoft services sparked fears of a mass cyberattack targeting the company, with many speculating that malicious actors were behind the disruption.
Although Microsoft wasn’t directly at fault, the incident underscored the vulnerability of global infrastructure to such disruptions, highlighting the world’s growing reliance on its services. As cyberattacks become more sophisticated, this event served as a stark reminder of the fragile nature of modern digital ecosystems.
Moreover, recently, Microsoft has encountered a series of backend changes that have occasionally derailed functionality across its services. There was a recent significant outage in Outlook, caused by a questionable code update, and yet another Outlook issue later in the month, further compounding the frustration for users. Also last week, another backend modification culminated in a licensing issue for Microsoft 365 Family subscribers, showcasing incorrect “Your subscription expired” alerts for some users.
Then there are the ongoing challenges Microsoft is facing around broader security concerns. In April 2024, the US Cyber Safety Review Board (CSRB) stated that Microsoft failed to adequately defend against a breach by Chinese hackers who exploited vulnerabilities in its Microsoft Exchange Online software during the Storm-0558 cyberattack in July 2023.
The CSRB’s assessment pointed to shortcomings in Microsoft’s defenses, arguing that the company should have been better prepared to prevent such an intrusion, which compromised sensitive US government email accounts.
More recently, Microsoft accounts have become a target for cyberattacks, potentially linked to Russian state-sponsored hackers, who are exploiting device code authentication phishing techniques. These attacks have proven highly effective, successfully compromising high-profile accounts within government agencies, research institutions, and prominent enterprise organisations.
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