Thanks to Marco for sending us a sample of yet another piece of crypto-ransom malware. The file was retrieved after visiting a compromised site (www.my- sda24.com) . Interestingly, the malware itself was stored on copy.com. 

Copy.com is a cloud based file sharing service targeting corporate users. It is run by Barracuda, a company also known for its e-mail and web filtering products that protect users from just such malware. To its credit, Barracuda removed the malware within minutes of Marco finding it.

At least right now, detection for this sample is not great. According to Virustotal, 8 out of 57 virus engines identify the file as malicious [1]. A URL blocklist approach may identify the original site as malicious, but copy.com is unlikely to be blocked. It has become very popular for miscreants to store malicious files on cloud services, in particular if they offer free trial accounts. Not all of them are as fast as Barracuda in removing these files.

[1] https://www.virustotal.com/en/file/1473d1688a73b47d1a08dd591ffc5b5591860e3deb79a47aa35e987b2956adf4/analysis/

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Johannes B. Ullrich, Ph.D.
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