
Claude Mythos: what an AI model that finds software flaws means for your security
What Claude Mythos is, who can use it, what the June suspension of access taught us and what a mid-sized company should change in its security.
Guide
This guide is for management boards and managers whose employees already use ChatGPT, Copilot or Gemini – on company or personal accounts. We explain which AI Act obligations already apply, what sensible rules for using AI consist of, and who should be responsible for what. At the end you will find a plan for introducing the rules in a mid-sized company.

The term AI governance simply means the rules and oversight for using AI in a company. It is not a thick document for lawyers, but answers to a few practical questions that each employee currently settles on their own.
Take a hypothetical 150-person trading company. A salesperson pastes a price list with discounts into a personal ChatGPT account to write a quote faster. An accountant asks another tool to summarise a supplier contract. No one has broken any rule, because there were none.
Rules for using AI should answer the five questions listed below. If no one in your company knows the answer to one of them, that is where to start.
The AI Act, the EU regulation on artificial intelligence, has been in force since 2024, and its obligations are being phased in. Some already apply; others were postponed by the 2026 Digital Omnibus package of amendments. The table below shows the dates that most often affect a mid-sized company.
An important caveat: the AI Act does not oblige every company to have an “AI policy” or an “AI systems register”. However, written rules and training are the simplest way to show that the company is building its employees’ AI knowledge as required by Article 4.
In Poland, the application of the AI Act is supervised by the Commission for the Development and Safety of Artificial Intelligence (KRiBSI). Its inspection powers and its ability to impose penalties apply from 28 October 2026. Independently of the AI Act, the GDPR still applies – any processing of personal data in an AI tool must have a legal basis.
| From | Obligation | Who it applies to |
|---|---|---|
| 2 February 2025 | Prohibited practices (Article 5), e.g. scoring people based on their social behaviour or emotion recognition in the workplace | Everyone who develops or uses AI |
| 2 February 2025 | Steps to build employees’ AI knowledge (Article 4) | Every company that uses AI systems at work |
| 2 August 2026 | Telling people they are talking to AI, and labelling realistic images, audio and video generated or altered by AI (Article 50) | Companies that, for example, have a chatbot for customers or publish such images or recordings |
| 2 December 2026 | Machine-readable marking of content (e.g. with a hidden watermark) in generative systems placed on the market before August 2026 | Mainly the providers of such systems |
| 2 December 2027 | Obligations for high-risk systems listed in Annex III, including human oversight and documentation | Companies using AI in, for example, recruitment, employee assessment or credit scoring |
| 2 August 2028 | Obligations for AI in regulated products (Annex I) | Manufacturers of, for example, machinery and medical devices that include AI |

When a company does not give employees AI tools, or bans them, people use them anyway – just on personal accounts. This is called shadow AI: using AI without the company’s knowledge or control.
The scale is large. According to a 2024 study by Microsoft and LinkedIn, 78% of people who use AI at work bring their own tools. Company data then ends up in services whose terms no one in the company has checked.
The answer is not a block but a secure alternative. Business versions of the tools have different terms from personal ones. For example, in Microsoft 365 Copilot prompts and responses are not used to train models, and Copilot only sees documents the user already has access to.
That last point has a flip side. If the payroll folder is open to the whole company, Copilot can find it. So permissions in SharePoint and Teams need to be reviewed before the tool is launched.
The rules are based on dividing data into a few classes and assigning permitted tools to each one. Employees do not need to know the law – they just need to know which class the document they want to paste belongs to.
The table below is an example for a mid-sized company. Adapt the class names and examples to your business, but do not create more than four or five, because no one will remember them.
| Data class | Examples | Where it may be used |
|---|---|---|
| Public | Website content, published catalogues, general questions | In any tool approved by the company |
| Internal | Procedures, meeting notes, internal presentations | Only in business versions of tools covered by a contract with the provider |
| Confidential | Price lists with discounts, contracts, financial data, source code | Only in tools approved for this class, with access control |
| Highly sensitive data | Health data, salaries with names, documents covered by professional secrecy | Only after a legal assessment, in solutions where you control where the data is processed |

Good rules for using AI do not tell employees “you must not”. They tell them what they can use safely, and how.
In a company of several dozen or several hundred people, you do not need new positions or a special committee. You need a clear division of tasks among people who already work in the company.
The most common mistake is treating AI as “everyone’s business”. In practice this means no one makes decisions, and the rules go out of date after a few months. Below is a division of responsibilities that works in a mid-sized company.
Introducing the rules in a mid-sized company usually takes a few weeks of work, not a project lasting many months. The order matters: first you check how things are, then you set the rules, and finally you give people tools and training.
After the first three months, review the reports and incidents. That is the best moment to improve the rules based on how people actually work.
The mistakes made with rules for using AI are the same whatever the industry. Most of them come from writing the rules for an auditor rather than for employees.
If you recognise any of the points below in your company, you do not have to start from scratch. Usually it is enough to simplify the document and appoint a person responsible for it.
For most uses, such as writing emails, summarising documents or helping with data analysis, rules, a company tool and training are enough. However, there are situations that call for more.
The first is high-risk systems under the AI Act, e.g. AI that assesses job candidates. From 2 December 2027, a company that uses them must, among other things, ensure human oversight and keep event logs. It is worth planning for this early, because it also applies to tools bought from vendors.
The second is highly sensitive data, e.g. medical data or data covered by professional secrecy. In that case the decision also covers where the AI processes the data: in the provider’s cloud or on the company’s own servers. We describe this choice in a separate comparison.
The third is companies that want to formally confirm their approach, e.g. for large customers. This is what ISO/IEC 42001:2023, the standard for AI management systems, is for. Certification is voluntary and mainly makes sense when customers expect it.
Related topics in the knowledge base
FAQ
The questions management boards ask most often after a first conversation about rules for using AI.
About this page
Sources
About the author
Kacper Włodarczyk
CEO of ALGORCOMP
Kacper specializes in implementing Microsoft 365 Copilot, Copilot Studio, Power Platform (Power Automate, Power Apps, SharePoint) and AI agents for mid-sized B2B companies in Poland. He leads dozens of projects covering AI strategy, Power Platform governance, document workflow automation and sales processes. In his writing he focuses on the practical side of AI adoption in organizations — from the first proof of concept to company-wide rollout — with particular attention to data security, compliance (GDPR, NIS2, the AI Act) and return on investment.
Meet the teamIn a free consultation we will look at which tools your employees use and help you set rules that can be introduced within a few weeks.
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