Malicious and Low Credibility URLs on Twitter during COVID-19

This study provides an in-depth analysis of a Twitter dataset around AstraZeneca COVID vaccine development released as a part of Grand Challenge, North American Social Network Conference, 2021. In brief, we show: i) the presence of malicious and low credibility information sources shared on Twitter messages in multiple languages, ii) the malicious URLs, often in shortened forms, are increasingly hosted in content delivery networks and shared cloud hosting infrastructures not only to improve reach but also to avoid being detected and blocked, iii) potential signs of coordination to promote both malicious and low credibility URLs on Twitter. We use a null model and several statistical tests to identify meaningful coordination behavior.