AI Assistant Security: Copilots and Your Data

AI assistants are now a key part of the modern workplace. In fact, McKinsey reports that as of 2025, 88% of the organizations it surveyed were already using AI in at least one business function. For background, see our recent coverage.

AI assistants like Microsoft Copilot can read emails, summarize documents, pull from Teams chats, and so much more, basically helping people get work done more efficiently. But these very capabilities that make them useful also come with a tradeoff. The more context an AI assistant can use, the greater the opportunity for sensitive information to get compromised.

Of course, Microsoft Copilot doesn't just pull information from your workload by itself. It works within the permissions already granted for your account. But that doesn't make every environment safe by default. You need to know how these tools handle data, where the risks hide, and how to set limits properly.

How Does an AI Assistant Access Your Data?

An AI assistant accesses information through the applications, data sources, and permissions it has. For Microsoft Copilot, this means Outlook, Teams, SharePoint, OneDrive, and other Microsoft 365 applications, via Microsoft Graph.

Here's the key point. Microsoft says Copilot only surfaces data that a user has permission to access. But that promise is as good as irrelevant if your permissions are all over the place.

According to a 2025 AI Data Risk Report cited by TechRadar, Copilot accessed roughly 3 million confidential records per organization before the first half of 2025. This should give you an idea of how much sensitive information an AI assistant can potentially come across.

What Are the Biggest AI Assistant Security Risks?

The biggest risks of AI assistants boil down to weak data governance. It has little or nothing to do with the AI itself. Let's take them one at a time.

Chat History Leakage

Every interaction with an AI assistant leaves a trace. Microsoft Copilot, for example, stores interactions by default unless an organization configures retention policies through Microsoft Purview.

Users can delete their chat history, and admins can set retention rules. But if nobody reviews those settings, sensitive conversations can sit there for a long time.

Excessive Permissions

According to Microsoft, Copilot can access information a user already has permission for. That sounds fine until you realize how messy permissions often are.

A file shared with “everyone” in SharePoint or a OneDrive folder with legacy access can suddenly become easy to find and summarize. AI doesn’t fix poor information governance. Instead, it makes the problems more visible.

Sensitive Information Upload

This one is the simplest and maybe the most common. Employees paste sensitive data into AI tools. They copy customer lists, financial figures, or internal notes into a prompt without thinking. The AI processes it, and now that data is in a system with its own storage and retention rules.

This actually happens a lot more than people know. A new report even suggests that as much as 26.4% of file uploads to GenAI tools contain sensitive information.

Sam Li, CEO of Thoropass, sums this situation up when he said that "AI adoption is moving faster than governance, and many organizations are now racing to catch up with compliance."

Prompt Injection Attacks

This is where things get tricky. Prompt injection happens when malicious instructions are hidden in content an AI assistant processes.

EchoLeak is a good example. Tracked as CVE-2025-32711 with a severity score of 9.3, this zero-click exploit lets attackers craft emails that could trigger data exfiltration with no user interaction. Microsoft fixed it in June 2025, and there's no evidence it was exploited again, but the lesson stands.

How Can You Reduce AI Assistant Security Risks?

Keeping organizational data safe when using AI assistants requires simple, practical rules. Here are a few of them.

Start with least privilege. Give people only the access they need, and clean up old file permissions.

Turn on audit logs and data loss prevention so you can see and stop risky activity.

Limit which apps Copilot can connect to, too. Every connection is another door.

Set a clear AI use policy. Name the approved tools and say what data stays out.

Look for a Copilot alternative that can give you what you want.

When looking at alternatives, how tools store chat history is a big differentiator. Lumo by Proton, for example, says it uses zero-access encryption for stored conversations. This feature can make sense for organizations where privacy is vital.

What Should You Check Before Adopting an AI Assistant?

Now that you know the biggest AI assistant security risks and how to reduce them, let's look at what to check before you roll anything out. Think of this as a pre-deployment checklist.

Start by auditing access. Who will have access to what across all connected systems and applications? Once you know where people have access, identify sensitive information and apply classifications or labels where needed. From there, review those existing permissions and remove anything that people no longer need.

Next, look into the vendor’s data-handling policies. Understand how conversations are stored, protected, retained, and deleted. Then figure out how you’ll monitor AI activity. You want to make sure the team knows what they can and can’t use the tool for.

This last point deserves more attention, as according to Microsoft's 2024 research, only 39% of employees using AI at work had received AI training from their employer.

Without relevant training, a technology that looks secure on paper can still be very risky because people don't understand the boundaries.

AI Assistant Security: Risk vs. Solutions

The table below summarizes the risks of AI assistants like Copilot and the possible solutions.

Risk	Solutions
Overshared Data	Apply least privilege and clean up old permissions
Prompt Injection Attacks	Limit app connections and patch known exploits
Chat History Leakage	Turn on audit logs, data loss prevention, and review retention rules
Sensitive Data Upload	Set a clear AI use policy and train staff
Poor Privacy	Compare storage methods and pick a privacy-focused option

FAQs

Can Microsoft Copilot see all my files?

No. It can only access what you already approved for it to see. However, if your permissions are too broad, that can still include a lot of information.

Is it safe to put data into an AI assistant?

It depends on the AI tool, how long it keeps data, as well as your company’s rules. The best option is to use only tools that are approved and built for business. Even then, keep your sensitive data out, unless you know exactly how it is stored and protected.

How do I stop employees from pasting data into AI tools?

You should have a policy that covers AI use in the workplace. But more than that, invest in AI training for your team. Also, importantly, make sure employees have an approved tool that’s easy to use. If your official AI assistant is difficult to use, they'll simply go find their own, no matter what the policy says.

Balancing AI Productivity and Security

AI assistants do not need special access rights to create security hiccups. The real issue comes down to fast information discovery mixed with messy file permissions and human error.

While we used Microsoft Copilot in this guide as a helpful example, these exact same issues apply to any tool you bring into the office. And the same solutions apply: secure your files, limit unnecessary access, and set clear rules for your team.