Data Leaves Your Business Every Day
Sensitive data leaves organisations constantly â through email attachments, cloud sharing links, USB drives, personal devices, and even printouts. Most of the time it is not malicious. An employee emails a spreadsheet of client details to their personal account to work from home. A staff member shares a financial report with the wrong external contact. A contractor copies project files to a USB drive for convenience.
The result is the same: sensitive business data ends up where it should not be, with no visibility or control.
What Data Loss Prevention Does
Data Loss Prevention (DLP) is a set of policies and tools that detect, monitor, and protect sensitive information from being shared inappropriately. DLP does not just block things â it provides visibility into how data moves through your organisation and applies rules based on the sensitivity of the content.
A DLP policy can warn a user before they send an email containing credit card numbers, block upload of files containing tax file numbers to personal cloud storage, alert administrators when sensitive documents are shared externally, and automatically encrypt emails containing confidential information.
DLP in Microsoft 365
If your business uses Microsoft 365, DLP capabilities are built in â but they are not enabled by default. Microsoft Purview DLP policies can monitor Exchange email, SharePoint sites, OneDrive accounts, Teams chats and channels, and endpoint devices (with the right licensing). Policies use sensitive information types â predefined patterns that detect data like Australian Business Numbers, tax file numbers, credit card numbers, Medicare numbers, and passport numbers. You can also create custom sensitive information types for your business-specific data.
Starting With DLP
Do not try to implement everything at once. Start with the most sensitive data and the most common leakage paths.
Phase 1 â Discovery: Turn on DLP in audit-only mode. This detects sensitive information across your environment without blocking anything. Review the reports to understand where sensitive data exists and how it moves.
Phase 2 â Warning: Enable policy tips that warn users when they are about to share sensitive information. This educates staff and catches most accidental leaks without disrupting workflows.
Phase 3 â Enforcement: For the highest-risk scenarios â sharing financial data externally, emailing client records outside the organisation â enable blocking policies. Allow users to override with a business justification that is logged for audit purposes.
Industry Applications
Legal practices: Client matter files are subject to legal professional privilege. DLP policies can prevent these files from being shared outside the firm or with unauthorised internal staff. Sensitivity labels combined with DLP provide a robust framework for client confidentiality.
Financial services: Client financial data, tax returns, and transaction records require protection under the Privacy Act and industry regulations. DLP policies detect and protect this data across email, file sharing, and endpoint devices.
Healthcare: Patient records and health information are among the most regulated categories of data in Australia. DLP policies help ensure this data is only shared through approved channels with appropriate protections.
Common Mistakes
Implementing DLP too aggressively too quickly frustrates staff and leads to workarounds that are less secure than having no DLP at all. Start with audit mode, communicate with staff about what DLP does and why, and implement blocking only for genuinely high-risk scenarios. DLP should protect the business without making it harder for people to do their jobs.
Beyond Technology
DLP technology is most effective when combined with clear data handling policies, staff training on data classification and handling, regular reviews of DLP reports and incidents, and incident response procedures for actual data breaches. Technology catches mistakes and enforces rules, but a culture of data awareness across the business is what prevents most leaks from happening in the first place.
Protect Your Data
If your business handles sensitive client or financial data and does not have DLP in place, you are relying entirely on staff behaviour to prevent data leaks. Contact TechAssist to implement Data Loss Prevention policies for your Microsoft 365 environment.
