SamSam ransomware said to be cause of this attack on the City of Atlanta. In this case, servers were susceptible to a Java exploit. Furthermore, there was an earlier exploit last year that didn’t seem to make mainstream news. In addition to keeping systems updated, keep in mind there are firewalls that block ransomware, viruses, malware, etc. and there are so-called firewalls that do not block these exploits. TTJ uses firewalls that do block exploits.