Update machinetag.json

Added Zombieware category, malware that has been abandoned by its operators, and despite being abandoned, new replications of the malware continue to appear in the wild.

malware_classification/machinetag.json

@@ -60,6 +60,10 @@
           "value": "Spyware",
           "expanded": "Spyware"
         },
+        {
+          "value": "Zombieware",
+          "expanded": "Zombieware"
+        },
         {
           "value": "Botnet",
           "expanded": "Botnet"