Internet reports about hundreds of usernames and passwords for document-sharing site Dropbox leaked and published on the 13th of October 2014, on Pastebin (an anonymous information sharing site) is not true.
The reports claim that an anonymous hacker had hacked close to 7m accounts.
“Recent news articles claiming that Dropbox was hacked aren’t true. Your stuff is safe. The usernames and passwords referenced in these articles were stolen from unrelated services, not Dropbox. Attackers then used these stolen credentials to try to log in to sites across the internet, including Dropbox. We have measures in place to detect suspicious login activity and we automatically reset passwords when it happens,” said Dropbox on their blog.
Nevertheless, it is helpful to change your passwords regularly.
Attacks like these are one of the reasons why Dropbox strongly encourage users not to reuse passwords across services. For an added layer of security, Dropbox recommends enabling 2 step verification on your account.