T1567.002sub-technique of T1567 Exfiltration Over Web Service
Exfiltration to Cloud Storage
ESXi · Linux · macOS · Windows5 pieces on this siteT1567.002 on attack.mitre.org
Adversaries may exfiltrate data to a cloud storage service rather than over their primary command and control channel. Cloud storage services allow for the storage, edit, and retrieval of data from a remote cloud storage server over the Internet. Examples of cloud storage services include Dropbox and Google Docs.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Data theft extortion response plan: verify the claim, find the way out, own the notification
An extortion demand with nothing encrypted, or your name on a leak site. Three questions run in parallel with three owners: is the claim real, what left and how, and what you are obliged to say and to whom. A plan for answering each one on evidence rather than on the attacker's framing.
Insider threat response plan: evidence, proportion and the employee who may have done nothing
The response where the usual instincts are wrong. Speed matters less than lawfulness, the suspect is a colleague with rights, and half of these turn out to be misunderstanding. A plan for investigating quietly, preserving what you would need, and being able to stand behind how you did it.
Suspected data theft by an insider
A resignation with unusual file access, a DLP alert, or an unexplained large transfer.
Data leaving with a person
A resignation with an unusual access pattern behind it, a bulk download, or a report from a manager.
Practise it
Labs, timelines, evidence packs and tabletop scenarios to work before you need to.
Seventeen hours at Calderbrook: from a password spray to data leaving
A constructed intrusion laid out against the clock and the ATT&CK tactics, following the same four stages as the guided labs. Eleven events, one of them inferred, and one tactic conspicuously missing.
how MITRE says to see it
Detection Strategy for Exfiltration to Cloud Storage
- Unusual processes (e.g., powershell.exe, excel.exe) accessing large local files and subsequently initiating HTTPS POST requests to domains associated with cloud storage services (e.g., dropbox.com, drive.google.com, box.com).
- Processes such as curl, wget, rclone, or custom scripts executing uploads to cloud storage endpoints. Defender perspective: detect chained events where tar/gzip is executed to compress files followed by HTTPS PUT/POST requests to known storage services.
- Applications or scripts invoking cloud storage APIs (Dropbox sync, iCloud, Google Drive client) in unexpected contexts. Defender perspective: detect sensitive file reads by non-standard applications followed by unusual encrypted uploads to external cloud storage domains.
- Unusual ESXi processes (vmx, hostd) reading datastore files and generating outbound HTTPS traffic toward external cloud storage endpoints. Defender perspective: anomalous datastore activity followed by network transfers to Dropbox, AWS S3, or other storage services.
what reduces it
- M1021 Restrict Web-Based Content. Web proxies can be used to enforce an external network communication policy that prevents use of unauthorized external services.