The files_antivirus component before 1.0.0 for ownCloud mishandles the protection mechanism by which malicious files (that have been uploaded to a public share) are supposed to be deleted upon detection.
When using an object storage like S3 as the file store, when a user creates a public link to a folder where anonymous users can upload files, and another user uploads a virus the files antivirus app would detect the virus but fails to delete it due to permission issues. This affects the files_antivirus component versions before 0.15.2 for ownCloud.