Input data and information sources
Incoming emails, invitations and shared documents also come from outsiders; EchoLeak required only a crafted email. Mailboxes, calendars and chats contain names, contact details and conversation content.
Also known as: Embedded workplace AI assistant (copilot)
Staff invoke the assistant directly in email, word processing, spreadsheets and chat; it accesses mailboxes and file storage using their permissions.
Understand the use case
The assistant drafts emails, summarises meetings and documents, and answers questions about anything the user is allowed to see. The UK government has trialled it, an IT services company is introducing it, and a Dutch municipality already uses it.
This page describes a typical system design. Actual data flows and permissions depend on your implementation.
System design and data flows
A user asks a question or gives an instruction in email, word processing, a spreadsheet or chat.
Incoming emails, invitations and shared documents also come from outsiders; EchoLeak required only a crafted email. Mailboxes, calendars and chats contain names, contact details and conversation content.
The assistant searches mailboxes, calendars and file storage using the user's permissions and passes the results to a language model.
The office application supplies the model with the instruction and available working context, such as an open document or a selected message. The model produces a suggestion within that application. Which other files are included depends on the connected services and permissions.
The assistant provides a draft, summary or answer with references to the content used.
A generated result is newly worded or created. To assess it, the instruction and context on which it is based must remain identifiable.
The user sends or saves the output, incorporating it into emails, documents and decisions.
Integration determines whether the result is simply displayed, adopted after approval or written directly into a business application. These variants differ in their data flows and permissions.
Explore the system design: Select a component to see its task, incoming and outgoing data, and role in the use case. The guided walkthrough explains each phase. Then use Yes, Uncertain and No to represent your specific system variant.
23 review first17 clarify9 baseline threats
The diagram shows the typical architecture. Select a component to see what happens there and adapt its features to your system. Enable “Analysis guidance” to see which threats need reviewing for this architecture. The page's checklist continues to describe the typical case.
None yet. Each change will appear here.
In this system design: 23 to review first, 17 to clarify, 9 baseline threats.
External access: Depends on your system
To clarify
Input: Part of every AI system
Review first
To clarify
Baseline for every AI system
Third-party content: Present
Review first
AI model: Part of every AI system
Review first
Baseline for every AI system
Provider service: Present
Review first
To clarify
Document collection: Present
Review first
To clarify
Memory: Depends on your system
To clarify
Training and feedback: Depends on your system
To clarify
Tools and interfaces: Depends on your system
To clarify
Result: Part of every AI system
Review first
To clarify
Baseline for every AI system
Business application or equipment: Depends on your system
person: Part of every AI system
Baseline for every AI system
Affected person: Depends on your system
Unapproved AI services: Depends on your system
To clarify
Supply chain and technical foundations: 5 baseline threats applying to every AI system
Baseline for every AI system
Generative AI assistant for staff
Works only with staff inputs, without access to mailboxes or storage
AI knowledge assistant (enterprise search)
Answers from a defined, editorially maintained document collection
Completes tasks independently in several steps, with its own permissions in business applications
Incoming emails, invitations and shared documents also come from outsiders; EchoLeak required only a crafted email. Mailboxes, calendars and chats contain names, contact details and conversation content.
The office application provider supplies the language model and search service.
The assistant searches mailboxes, calendars, chats and file storage for relevant content. It formulates answers from the emails and documents it finds.
Depending on the product, the assistant calls functions in other applications or extensions. Depending on the product and settings, the assistant sends emails, creates appointments and edits files itself, or only provides drafts.
Using a provider does not automatically determine where processing takes place. Storage location, subcontractors, deletion periods and use for training must be checked for the specific deployment.
Assess risks and determine measures
Record data, participants, interfaces and permissions. Resolve uncertain characteristics in the model.
Relate review candidates to actual data flows: what could happen, and who would be affected?
Assess impacts and likelihood in the deployment context. The number of review candidates is not a risk score.
Select appropriate controls, assign responsibilities and define effectiveness checks. Document residual risks and approvals.
A total of 49 threats from the threat catalogue may be relevant to this use case.
An outsider sends an email containing hidden instructions that the assistant reads during its next search. It follows them even though the user has never opened the email.
Exfiltration from ML Application
Injected instructions make the assistant embed internal content in a link or image. When the application loads the image, the data reaches an external server, as happened with EchoLeak.
Cross-Tenant Leakage (Multi-Tenant Vector DB)
Folders containing personnel or board records are accidentally shared with everyone. The assistant finds them and reveals their contents to anyone who asks.
RAG-Specific Attacks (Document Poisoning)
Someone places a document with false information in shared storage. The assistant cites it as a source and spreads the error in answers to many staff members.
Training data or an adopted base model can introduce hidden triggers for misbehaviour.
Listed because of this characteristic
Sleepy Agent (Time/Event-Triggered Hidden Instructions)
An instruction-following model can change behaviour at a particular time or event.
Listed because of this characteristic
Users can override the system's working instructions through their inputs.
Listed because of this characteristic
People requesting generated content may try to bypass intended limits.
Listed because of this characteristic
Carefully crafted queries can reveal system instructions, which must therefore contain no secrets.
Listed because of this characteristic
Complex or high-volume inputs can exhaust model computing resources.
Listed because of this characteristic
Targeted queries can recover some personal or protected training data from the model.
Listed because of these characteristics
Sensitive Information Disclosure
Confidential content can appear in answers, supplied context or logs.
Listed because of these characteristics
Hate Speech and Discrimination
Open-ended generated content can contain discriminatory or hateful statements.
Listed because of these characteristics
Freely generated answers can use an inappropriate tone.
Listed because of these characteristics
Open-ended content can depict violence or assist dangerous actions.
Listed because of these characteristics
Answers on controversial topics may require separate editorial review.
Listed because of these characteristics
Open-ended content can facilitate unlawful acts. The required scrutiny depends on purpose and users.
Listed because of these characteristics
Open-ended content can be used for harassment.
Listed because of these characteristics
Generated suggestions can cross ethical boundaries in the specific context.
Listed because of these characteristics
Generated images, voices and texts can deceive or impersonate people.
Listed because of these characteristics
Generated content can facilitate fraud, for example through forged messages or documents.
Listed because of these characteristics
Synthetic content can be presented as authentic and spread misleadingly.
Listed because of these characteristics
Factual Inconsistencies (Hallucinations)
Generated text can invent facts or distort them during rewriting.
Listed because of this characteristic
Up to 17 further threats may apply, depending on your system design. Nine threats need to be reviewed for every AI system.
Each Yes adds further threats to your checklist, up to 17 in total. If you cannot yet answer a question, include its threats in your review.
How your system is built
How you operate the system
In some office applications, the assistant also generates images, for example for presentations.
If yes, add
If yes, add
Some products remember preferences and information from earlier conversations.
If yes, add
Depending on the product, the assistant calls functions in other applications or extensions.
If yes, add
Depending on the product and settings, the assistant sends emails, creates appointments and edits files itself, or only provides drafts.
If yes, add
If yes, add
If yes, add
If yes, add
In spreadsheets, the assistant also writes formulas and scripts.
If yes, add
If yes, add
These questions arise for almost every AI system.
If yes, add
If yes, add
If yes, add
If yes, add
If yes, add
Measures for the priority review areas are expanded. Each linked measure explains how to implement it.
Controls for the remaining threats are available on their pages in the threat catalogue.
For every AI system Applies since 2 February 2025.
Depending on use Review trigger since 2 August 2026.
Applies if staff or appointed representatives operate or use AI systems.
Applies since 2 February 2025.
Detailed obligations
Applies if texts produced with the assistant are published on matters of public interest without human editorial review and responsibility.
Applies since 2 August 2026.
Detailed obligations
Staff knowingly invoke the assistant in their office application, making it obvious that they are using an AI system.
Detailed obligations
Classify your system with the quick checker All obligations in the obligations compass
Review these threats for every AI system, whatever its purpose.
If any of these features does apply to your system, add the listed threats.
Does the system determine its next steps itself based on earlier results?
The assistant handles individual instructions and does not plan its own sequence of tasks.
If yes, add
Can people outside your organisation use the system, including without login?
If yes, add
Is the system intended to maximise a specified metric, such as revenue, utilisation or clicks?
If yes, add
GOV.UK, Microsoft 365 Copilot Experiment: Cross-Government Findings Report
Twelve UK government organisations trialled the assistant with 20,000 staff from September to December 2024.
Bechtle AG, Bechtle introduces Microsoft 365 Copilot for 5,000 employees, Press release, 2024 According to the deployer
The company states that it is introducing the assistant for 5,000 staff.
Dutch Algorithm Register, Microsoft M365 Copilot, Gemeente Raalte
The municipality has used the assistant since January 2025. It accesses documents, emails, calendars and chats visible to the signed-in user.
Checkmarx, EchoLeak (CVE-2025-32711) Shows Us That AI Security Is Challenging
A crafted email in a mailbox was enough to make Microsoft 365 Copilot disclose internal data without user involvement. The vulnerability is recorded as CVE-2025-32711.
MITRE ATLAS, atlas-data CHANGELOG
Case studies AML.CS0026 and AML.CS0059 cover assistants of this kind.
Updated: 30 September 2026. Review checklist rules version 0.3.2, threat catalogue version 2026.10.24.2. How these pages are structured