Starting from MISP 2.4.114, a decaying feature is available to apply decaying on attributes in your MISP instance. MISP comes with a set of default decaying models which
can be customised by the users. This repository contains all the default models.
For more information about decaying and expiring attributes/indicators in MISP, the training materials [MISP and Decaying of Indicators](https://www.misp-project.org/misp-training/a.5-decaying-indicators.pdf) is a good start.