Azure DDoS Attack: A multi-vector tactic to flood the network

Microsoft Azure confirmed a nine-hour outage on Tuesday, 27th July 2024 , which took down and disrupted multiple Microsoft 365 and Azure services worldwide, was triggered by a distributed denial-of-service (DDoS) attack. The outage impacted Microsoft Entra, some Microsoft 365 and Microsoft Purview services (including Intune, Power BI, and Power Platform), as well as Azure App Services, Application Insights, Azure IoT Central, Azure Log Search Alerts, Azure Policy, and the Azure portal.(Source :www.bleepingcomputer.com/news/microsoft).

In the evolving landscape of cyber threats, Distributed Denial-of-Service (DDoS) attacks remain one of the most challenging forms of cyberattacks to defend against. In a significant incident in 2023, Microsoft Azure, a leading cloud service provider, became the target of one of the largest DDoS attacks ever recorded. This event not only tested Azure's defenses but also highlighted the growing sophistication of cyber threats in the cloud computing era.

On that note, this is not the first DDoS attack to effect Azure.

Microsoft Azure has faced a significant number of DDoS attacks, particularly in recent years as the frequency and complexity of such attacks have escalated. Notable incidents include:

2021 Surge in Attacks: In the second half of 2021 alone, Azure mitigated over 359,000 unique DDoS attacks, with an average of 1,955 attacks per day. The largest of these was a record-breaking attack in November 2021 that reached a peak of 3.47 Tbps, the largest DDoS attack ever recorded at that time. This attack was part of a broader trend of increasingly large-scale and sophisticated DDoS attacks against cloud services (Microsoft Azure) (Windows Central)

2023 Outages: In June 2023, Microsoft confirmed that a series of outages affecting Azure, Outlook, and other services were caused by Layer 7 DDoS attacks. These attacks, attributed to the threat actor group known as Storm-1359 (also referred to as Anonymous Sudan), targeted web-accessible portals and caused significant service disruptions (BleepingComputer).

2024 Outage : The attack was identified as a DDoS attack targeting Layer 7, which is the application layer of the OSI model. This type of attack overwhelms the targeted services with a massive number of requests, causing them to slow down or become entirely inaccessible. The attack exploited multiple virtual private servers (VPS) and rented cloud infrastructure to execute the attack, demonstrating the attackers' access to significant resources.

The Nature of the Attack

The attack was a Layer 7 DDoS attack, which targets the application layer of the OSI model. Unlike traditional DDoS attacks that flood a network with traffic, Layer 7 attacks overwhelm specific applications with a massive volume of requests, causing them to slow down or crash. In this case, the attack overwhelmed Azure’s infrastructure, affecting services like Microsoft 365, Microsoft Entra, Azure App Services, and others.

The attackers utilised multiple virtual private servers (VPS) and rented cloud infrastructure to launch the attack, demonstrating their access to significant resources and their ability to coordinate a large-scale assault. The attack was initially mitigated by Azure’s DDoS protection mechanisms, but an error in the implementation of these defenses exacerbated the impact rather than reducing it (BleepingComputer) (BleepingComputer).

Impact on Services

The DDoS attack led to widespread service disruptions, affecting both enterprise and individual users. Services like Azure IoT Central, Azure Policy, and the Azure portal experienced significant outages. The attack highlighted vulnerabilities in Azure's defense mechanisms, which initially struggled to handle the unexpected surge in traffic. This incident not only caused inconvenience but also raised concerns about the resilience of cloud services against increasingly sophisticated cyber threats (TechRepublic).

Microsoft’s Response

Microsoft quickly identified the nature of the attack and took steps to mitigate its impact. This included implementing networking configuration changes and rerouting traffic through alternate paths. Despite these efforts, the scale of the attack and the initial missteps in defense management prolonged the outage.

Microsoft has committed to a full investigation of the incident and plans to release a Preliminary Post-Incident Review (PIR) within 72 hours of the attack, followed by a more detailed report. This transparency is crucial for rebuilding trust with customers and learning from the incident to improve future defenses (BleepingComputer).

Broader Implications for Cloud Security

The 2024 Azure DDoS attack is a stark reminder of the evolving nature of cyber threats. As cloud services become more integral to business operations worldwide, the need for robust and scalable security measures has never been more critical. This incident demonstrates that even the largest and most sophisticated platforms are not immune to vulnerabilities.

For businesses, this attack highlights the importance of having contingency plans and understanding the shared responsibility model in cloud security. While cloud providers like Microsoft invest heavily in protecting their infrastructure, customers must also ensure that their applications and data are secure and that they are prepared for potential disruptions.

Conclusion

The 2024 Azure DDoS attack serves as a wake-up call for both cloud service providers and their customers. It underscores the need for continuous improvement in cybersecurity defenses and the importance of being prepared for the increasingly sophisticated tactics employed by cybercriminals. As the investigation continues, the lessons learned from this incident will likely shape the future of cloud security practices.

By understanding the nature of these threats and the responses required, businesses can better protect themselves in an era where cyberattacks are not just a possibility, but an ever-present reality.