Hello @COR3Infra,
welcome to this moderated Azure community forum.
You ran into an unfortunate situation. There are multiple angels to this story though.
In a production subscription, the Azure resource spendings are not limited, your production must not be interrupted when suddenly more resources are used.
So, you are lucky you encountered this in a subscription with a spending limit.
Normally you need to set warnings and alerts when you spend more than you expected:
Next, check the DDOS protection offered by Azure (together with the Application Gateway).
The Azure portal also offers elaborate views and forecasts on the costs, typically per resource group of subscription:
Take some time to drill through the cost management per subscription or per resource group.
There are even some free training modules on this topic.
Depending on the resource, you can either disable or delete them if you really want to limit the cost impact (like disabling an Azure Function or disabling a database).
Better is to design your architecture with hacking attempts and how to protect yourself in mind already.
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