Criminals are targeting Dropbox users with a bogus password reset email that, when clicked, infects the victim's machine with a Zeus-family malware.
The new Zeus campaign was uncovered by cloud security provider Appriver. The Appriver researchers reported that the message attempts to stop users checking if their old password works, by listing it as "dangerous".
"A new campaign just started up involving some fake Dropbox password reset emails. The emails come in with a sad computer face claiming the recipient has requested a password reset and their old password is now ‘dangerous'," read the report.
"The email itself contains a link that, when clicked, leads the user to a page saying their browser is out of date and they need to update it. Clicking anything in the linked notification page downloads a file ieupdate.exe. The file is a Trojan that is part of the Zeus family."
Dropbox has since released a statement confirming it has taken action to try and deal with the scam. However, the use of Zeus remains troubling.
Zeus is a notorious banking Trojan family of malwares that has been plaguing the security community for years. The malwares are designed to steal their victims' financial information. The Zeus malwares are commonly used by criminal groups. In May, McAfee reported Zeus and its variants account for 57.9 percent of all botnet infections.
The Appriver researchers reported tracking the latest Zeus campaign to 54 unique domains, all of which were hosted at the dynamooblog.ru web domain in Russia.
The attack is one of many to target Dropbox users. The propensity of the attacks has led numerous figures within the security and technology industry to list Dropbox as unfit for corporate use.
Aaron Levie, chief executive of enterprise cloud storage firm Box, told V3 that enterprise businesses will have to stop using services like Dropbox if they hope to regain control of their networks.
F-Secure web reputation service expert, Christine Bejerasco said the failure of online services such as Facebook, Twitter and Dropbox to adequately test their security before launching as a key reason for the current boom in cyber crime.