We've noticed a new scam increasing in the last few days emails being sent disguised as being from Dropbox, the subject is typically along the lines of "shared "MonthlyStatement_AUG15.pdf with you". The email is pretending to come from email@example.com but the actual address is firstname.lastname@example.org this will likely be different with each email received.
The aim of the email is to get you to click on the link to download the fictional attachment such as a PDF but you actually download a zip file. The contents of the zip file likely contain malware or viruses to infect your computer and cause havoc and or spread itself to other users.
If you receive an email that looks like it's from Dropbox from a user your are not expecting do not click on the links, best to delete the email immediately.