The dark web, often linked with illegal activities, can be monitored with different solutions. However, these tools are typically purpose-specific and designed for unique use cases. In this study, we propose a flexible and scalable framework that facilitates the easy integration of new workflows for dark web analysis. The design is based on the control, logic and operations layers, supplemented by a tools module, logs management, asynchronous message-based communication and a database. The implementation maps the features into a microservice approach, utilizing the open-source technologies Docker Swarm, Kafka, ELK Stack (Elastic Search, Logstash and Kibana), and PostgreSQL. A workflow to scrape web elements of Tor onion services is deployed and validated, demonstrating considerable framework performance despite the time-consuming task of navigating the dark web. Over 16 h, the framework collected over half million onion domains (84,371 unique ones) and made 78,555 accesses to them.