This past week, I encountered an all too common situation — a user gets a targeted phishing attempt. Despite a strong training program, the user opens the attachment and gets infected with ransomware.
For many organizations, this would have resulted in a disaster. Ransomware would have encrypted files on any servers, and the organization would have been forced to either restore the files from a backup, assuming they had them, or to hold their nose and pay a ransom.
The news was better, however, for the organization I mentioned above.
Fortunately, the premise of their security planning was that someone would eventually shoot them in the foot. With a security plan that assumed this, they had a depth of layered controls to help. While their anti-virus software did not prevent the infection, it did recognize and send an alert about it, after the fact. In the meantime, their web filtering appliances and their DNS service provider, recognizing the call from the infected PC to a command and control server to get an encryption key, blocked access. Since the ransomware client never got the key, it did not encrypt any files. The blocking of command and control access provided the extra time needed to get the PC pulled out of service and repaired.
Source: Computerworld.com | Security