BibTeX does not have the right entry for preprints. This is a hack for producing the correct reference:
@booklet{EasyChair:7077,
author = {Intan Maratus Sholihah and Hermawan Setiawan and Olga Geby Nabila},
title = {Cyber Threat Intelligence as an Knowledge Sharing Platform},
howpublished = {EasyChair Preprint 7077},
year = {EasyChair, 2021}}