In order to address the fast-evolving challenges with respect to advanced forms of cybercrimes enabled by fully available state-of-the-art technologies (Crime-as-a-Service), there is a need for LEAs to form and apply cutting-edge collaboration frameworks that will break communication silos within the wider judicial ecosystem. These frameworks may span in numerous pillars, such as (i) regulated, privacy-preserving and easy sharing of information related to criminal activities enabling cross-border agency-to-agency collaboration in a transparent and explainable manner; (ii) joint criminal investigation further facilitated by beyond state-of-the-art tools enabling real-time collaboration and the full exploitation of distributed digital infrastructures to enhance cybercrime intelligence; (iii) exchanging different types of expertise (cybersecurity experts, forensics experts, lawyers and stakeholders from the judicial ecosystem, psychologists, social scientists) to realise cutting edge investigative approaches; and (iv) knowledge and best practices sharing with respect to trainings and cybercrime awareness. GANNDALF will set new grounds for the fight against advanced forms of cyber threats and cyber-dependent crimes; it will (i) realise cutting-edge agency-to-agency data sharing mechanisms, optimising the balance between transparency and privacy based on the needs of each LEA; (ii) deploy a modular, decision-support toolbox that will comprise not only ground-breaking technologies for collaborative investigation, prediction and identification of advanced forms of cyber threats, but also optimisation mechanisms enabling the full exploitation of these technologies; (iii) build on the above 2 offerings and deliver a customizable, collaborative crime investigation sandbox for scenarios, hypotheses analysis and crime investigation; and (iv) facilitate policy drafting, training and citizens’ engagement via innovative mechanisms that will realise the Cyber Hygiene 2.0 visiοn.