255. Adversaries Use Azure Functions as C2

Hello everyone!

Yes, another legitimate service is abused by adversaries for C2 channel. And this time it's Azure Functions.

Azure Functions is a serverless, event-driven platform that lets you run small pieces of code (functions) in the cloud without provisioning or managing servers. And according to this report, it's now used by threat actors as C2.

As always, we can hunt for such behavior focusing on suspicious processes:

event_type: "dnsreqwin"

AND

dns_rname: "azurewebsites.net"

See you tomorrow!

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