The global pandemic caused an abrupt shift to remote work among enterprise knowledge workers, which in turn resulted in an increase in risky behavior. Attackers immediately tried to capitalize on the pandemic, with COVID-19-themed phishing emails, scams, and Trojans. At the same time, techniques used in more sophisticated cyberattacks continued to evolve. We observed shifts in the popularity of different cloud apps, with OneDrive decreasing in popularity as a malicious file delivery vehicle while other apps like Sharepoint and Box increased in popularity. Attackers also shifted techniques for initial delivery, with malicious Microsoft Office document files increasing more than six-fold to match portable executable files in popularity. This blog post highlights both of these trends as it explores the shift in the cloud apps and file types used for malicious file delivery in the past year, from September 2019 through the end of September 2020.