Power Automate: when a three-click flow exfiltrates your data
With a standard Microsoft 365 licence, any user can build a Power Automate flow that copies every incoming attachment to personal storage. No alert, no approval. The Power Platform is a remarkable productivity tool, but it opens an exfiltration channel that many organisations do not monitor.
The risk: connectors to the outside world
Power Automate relies on hundreds of connectors. Some point to consumer services: personal email, personal cloud storage, social networks. Others, such as the HTTP connector, can send data to any address. A flow using Outlook or SharePoint as a trigger and a personal service as an action is enough to move data out continuously, under the user's identity and without passing through your email controls.
The scenario is not only malicious: a well-meaning employee who wants to "get my files on my phone" builds exactly the same flow.
The default environment
Every tenant has a default environment in which all licensed users can create apps and flows. This is where spontaneous creations pile up, often with no identified owner after someone leaves. Minimal governance means:
- renaming the default environment to signal its personal-productivity purpose;
- applying the most restrictive DLP policy to it;
- restricting creation of new environments to administrators;
- creating dedicated environments, with suitable rules, for business solutions.
Additional governance features, such as Managed Environments, are available depending on Power Platform licensing; they evolve regularly.
Power Platform DLP policies
Separate from Purview DLP, Power Platform data policies classify connectors into three groups:
| Group | Effect |
|---|---|
| Business | Connectors that can be used together in the same app or flow |
| Non-business | Can be used together, but never combined with a business connector |
| Blocked | Cannot be used |
Placing Microsoft 365 connectors in the business group and personal services in the blocked group prevents the exfiltration scenario described above. Some core Microsoft connectors cannot be blocked. For certain connectors, finer control over actions or endpoints is also possible.
Rolling out without breaking things
- Inventory existing flows and apps, for example with the PowerApps administration cmdlets or the Center of Excellence starter kit.
- Identify the connectors actually in use and their owners.
- Warn affected makers before enforcing a policy: flows that violate it are suspended.
- Apply a tenant-wide policy first, then environment-specific policies.
Watch out. Connectors newly added by Microsoft land in the default group defined in the policy. If that default group is "Business", every new connector can be combined with your data without prior review.
What an audit checks
- Whether a Power Platform DLP policy covers the default environment.
- How connectors to personal services and the HTTP connector are classified.
- The default group assigned to new connectors.
- Who can create environments.
- Orphaned flows or flows owned by disabled accounts.