Dropbox has begun investigating complaints that users are receiving spam to email addresses only associated with their accounts at the file-sharing service.
The spam, sent to addresses only used for Dropbox accounts, advertises a particular gambling website, according to users on Dropbox's forum. The behaviour has sparked concerns that Dropbox's database has been harvested or otherwise compromised, although this remains unconfirmed. One other possible explanation is that a third-party app which integrates with Dropbox is to blame for the leak.
Spambots striking it lucky and randomly hitting a run of unique and private email address associated with Dropbox seems improbable, especially given the volume of users who are complaining about "Dropbox spam" on Twitter and elsewhere. Complaints on Dropbox's own forums suggest the problem is limited to European users of the file-synching service.
In response to these concerns, a Dropbox staffer said it had called in external security experts to help with an investigation into the spam run.
We wanted to update everyone about spam being sent to email addresses associated with some Dropbox accounts. We continue to investigate and our security team is working hard on this. We’ve also brought in a team of outside experts to make sure we leave no stone unturned.
While we haven’t had any reports of unauthorized activity on Dropbox accounts, we’ve taken a number of precautionary steps and continue to work around the clock to make sure your information is safe. We’ll continue to provide updates.
The Dropbox staffer added that a 30-minute outage on Dropbox's site early on Tuesday afternoon was "not caused by any external factor or third party" and apparently was not linked to the current junk mail unpleasantness. ®