Since mid-April 2024, Microsoft has observed an increase in defense evasion tactics used in campaigns abusing file hosting services like SharePoint, OneDrive, and Dropbox. These campaigns use sophisticated techniques to perform social engineering, evade detection, and compromise identities, and include business email compromise (BEC) attacks.
Microsoft's OneDrive file-sharing program can be used as ransomware to encrypt most of the files on a target machine without possibility of recovery, partly because the program is inherently trusted by Windows and endpoint detection and response programs (EDRs).
