Researchers at Cisco's Talos Unit recently published research exploring the tactics, technics and procedures of the global malvertising ecosystem. Craig Williams is head of Talos Outreach at Cisco, and he guides us through the life cycle of malicious online ads, along with tips for protecting yourself and your organization.
The research can be found here: 
https://blog.talosintelligence.com/2019/07/malvertising-deepdive.html