File sharing is a classic operation performed by many people on a daily basis. If you can share files using big players like Dropbox or all the *Drive ("One", "Google", etc), there exists a lot of free alternatives that help to easily share files with peers. Because, still today, many organizations do not provide an "official" (read: promoted, supported, and monitored) service, users are always looking for alternatives. There are plenty of tools available like Lufi[1] or transfer.sh[2] (they are plenty of others). The sample that I spotted yesterday was delivered through the second one.