Public cloud services have seen a massive growth in recent years as organizations have started to move their infrastructure to the cloud. This enables the organizations to take advantage of the dynamic infrastructure and reduced infrastructure costs that cloud computing brings. Public cloud services also bring new security challenges however, as the infrastructure is running as instances in a shared environment. The goal of this thesis is to explore file confidentiality challenges in the cloud. This is done in practice by developing a prototype that can extract file(s) from ongoing file transfers occurring on a virtual machine by analyzing its memory from the physical machine (VMM). The prototype shows that it is possible to extract the files, but that the success rate depend on a number of factors such as the network speed the file(s) are downloaded at and the size of the files. Throughout the thesis these factors have been measured and analyzed in order to better understand how they affect the prototype and the extraction of files from file transfers in general.