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Netskope has discovered a malware campaign that takes advantage of multiple cloud apps throughout the kill chain. The campaign, which we have dubbed “CloudSquirrel,” has been in operation since June 2016 and has the intention of stealing and exfiltrating user data within the Outlook address book and, more importantly, usernames and corresponding passwords for email accounts configured in any of the email clients.
Likely originating in Brazil (based on names and parameters), CloudSquirrel is written in Java and is being distributed using ServInt’s Jelastic platform-as-a-service(PaaS). Jelastic redirects to the CloudApp collaboration platform which, in turn, uses Amazon AWS for its backend cloud services. This cloud malware actively uses Dropbox for its command and control communications.
We have observed the CloudSquirrel attack arriving via an email phishing attack. This attack email attempts to trick its victim into opening it with a “tax invoice” or other important-sounding link. Once open, CloudSquirrel infects users by downloading additional malicious encrypted payloads via a JAR file. Those can include information and password stealers. Once the malware establishes a connection with its command and control hosted in Dropbox, it’s commands masquerade as plain text files with fake extensions lik