Four hidden M365 vulnerabilities that could be costing your business

Microsoft 365 (M365) powers millions of businesses worldwide and widely adopted in New Zealand. But beneath the surface of everyday productivity lies a network of potential vulnerabilities that most organisations never discover until it’s too late.

At Securecom, we conduct M365 health checks across New Zealand businesses. Time and again, we uncover the same hidden issues that drain budgets, expose data, and frustrate users.

The good news?

Most of these problems are preventable with the right knowledge and approach.

Here are the four most common M365 vulnerabilities we discover and what you can do about them.

Vulnerability #1 – Security gaps leaving your data exposed

Default security settings in M365 often provide basic protection at best. Many organisations assume Microsoft handles all security, leaving critical gaps in their defence.

What this might look like:

Your organisation could have dozens of guest users with access to sensitive files. These external accounts might have been created for temporary projects but never removed. Without proper policies, these guests could download confidential documents to personal devices.

What Securecom typically finds:

• Unlimited external sharing enabled across SharePoint and Teams
• Multi-factor authentication disabled for admin accounts
• No conditional access policies restricting access from risky locations
• Overprivileged user accounts with unnecessary admin rights
• Legacy authentication protocols still enabled

Action you can take today:

1. Review your external sharing settings in the SharePoint admin centre
2. Enable multi-factor authentication for all admin accounts immediately
3. Run a user access review to identify inactive or unnecessary accounts
4. Check your sign-in logs for unusual activity patterns

Vulnerability #2 – Compliance risks hiding in plain sight

M365’s default settings rarely align with industry-specific compliance requirements. Data retention, privacy controls, and audit capabilities often need configuration.

What this might look like:

A healthcare provider might assume their patient data is compliant because it’s “in the Microsoft cloud.” However, they could have no data loss prevention policies, no audit logging for file access, and sensitive information being shared via personal OneDrive accounts.

What Securecom typically finds:

• No data classification or labelling policies
• Audit logging disabled or set to minimum retention
• Personal OneDrive accounts containing business-critical data
• No data loss prevention rules for sensitive information
• Teams recordings stored indefinitely without governance

Action you can take today:

1. Enable audit logging across all M365 services
2. Implement basic data loss prevention for credit card numbers and personal information
3. Review where your Teams recordings are stored and for how long
4. Check if sensitivity labels are configured for your industry

Vulnerability #3 – Cost inefficiencies bleeding your budget

M365 licensing is complex, and most organisations end up paying for features they don’t use or buying the wrong licence types for their needs.

What this might look like:

A mid-sized company might be spending thousands annually on premium licences for users who only need basic email and file sharing. After optimisation, we reduce costs, right-size licensing and improve functionality for their power users.

What Securecom typically finds:

• Users assigned premium licences who only need basic features
• Duplicate licences across different platforms
• Storage overage charges that could be avoided with archiving
• Multiple subscriptions for the same functionality

Action you can take today:

1. Review your M365 usage reports to identify inactive users
2. Audit licence assignments against actual user needs
3. Check for unused applications like Power BI Pro or Project Online
4. Review your storage usage and implement retention policies

Vulnerability #4 – Backup and recovery blind spots

Many businesses assume Microsoft’s built-in protection equals comprehensive backup. Microsoft provides availability, not complete data protection against deletion, corruption, or malicious attacks.

What this might look like:

A consulting firm could lose months of project files when an employee accidentally deletes a SharePoint site. They might discover that Microsoft’s recycle bin only retains items for 93 days, and the deletion happened months earlier. The cost of recreating lost work could reach tens of thousands of dollars.

What Securecom typically finds:

• No third-party backup solution for M365 data
• Reliance on recycle bins with limited retention periods
• No tested recovery procedures for different scenarios
• SharePoint sites with no versioning enabled
• Teams chat data not included in any backup strategy

Action you can take today:

1. Test your ability to recover a deleted SharePoint site from six months ago
2. Enable versioning on critical SharePoint document libraries
3. Document your current backup and recovery capabilities
4. Identify what M365 data would be unrecoverable if deleted today

The cost of inaction

These vulnerabilities don’t exist in isolation. A security gap can become a compliance violation. Poor user experience leads to shadow IT adoption. Cost inefficiencies compound monthly.

The businesses we work with often discover that addressing these issues delivers immediate returns. Improved security reduces risk exposure. Better licensing saves thousands annually. Enhanced user experience boosts productivity across the entire organisation.

Getting professional help

While the actions above provide a starting point, comprehensive M365 optimisation requires deep expertise and specialised tools. At Securecom, our M365 health checks use advanced analysis techniques to uncover issues that standard admin tools miss.

As a Microsoft Modern Work and Security Solution Partner with over 20 years of experience, we’ve seen these patterns across hundreds of organisations. Our systematic approach identifies not just what’s wrong, but prioritises fixes based on business impact and risk.

Ready to discover what’s hiding in your M365 environment?

We’re offering comprehensive M365 health checks to help New Zealand businesses optimise their Microsoft investments. Our assessment covers all four areas above and provides a detailed action plan tailored to your specific needs.

Don’t let hidden vulnerabilities continue costing your business. Take action today.