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Security This document provides advice on the naming of threat actors (also known as malicious actors). The objective is to provide practical advices for organisations such as security vendors or organisations attributing incidents to a group of threat actor. It also discusses the implication of naming a threat actor towards intelligence analysts and threat intelligence platforms such as MISP ].

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 .

Before creating a new threat actor name, you MUST consider a review of existing threat actor names from databases such as the threat actor MISP galaxy . Proliferation of threat actor names is a significant challenge for the day-to-day analyst work. If your threat actor defined an existing threat actor, you MUST reuse an existing threat actor name. If there is no specific threat actor name, you SHALL create a new threat actor following the best practices defined in this document.

Naming a threat actor could include specific sensitive reference to a case or an incident. Before releasing the naming, the creator MUST review the name to ensure no sensitive information is included in the threat actor name.

The authors wish to thank all contributors who provided feedback via Twitter.