On April 15th, Tech Republic ran an article of interest to those of you dealing with network security. Blogger Michael Kassner’s article “Dropsmack: Using Dropbox to steal files and deliver malware” detailed his discovery at this year’s European Black Hat convention of a presentation made by penetration tester Jacob Williams. Williams’ presentation was titled “Dropsmack: How Cloud Synchronization Services Render Your Corporate Firewall Worthless”. In it, he describes how he was able to spear-phish the CEO of a client company and access the CEO’s Dropbox account. From there, even though he could not read the files inside directly, he was able to install malware to them to be synchronized down to the CEO’s workstation, where they could cause damage or seek out data to send back out. The malware uses the Dropbox synchronization service as a “Command and Control” (C2) channel. Chilling reading!