Possible Dropbox API C2 Channel via Non-Browser DNS Query

ATT&CK techniques

C2 → Exfiltration

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1102.002Bidirectional Communication
Exfiltration
- T1567.002Exfiltration to Cloud Storage
Impact

What it detects

This rule detects DNS queries for the Dropbox API endpoints api.dropboxapi.com and content.dropboxapi.com made by a process that is not a browser or the Dropbox client. In the WithSecure C2 and Exfiltration Lab 3 a C3 channel abuses Dropbox as a legitimate web service for command and control and data exfiltration through sequential upload, download and delete calls. Attackers hide C2 inside trusted cloud storage traffic to blend with normal usage.

Reporting behind it

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Possible Dropbox API C2 Channel via Non-Browser DNS Query

Pivot detection · T1567.002 · 9 related

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