Fix winlogbeat powershell event processing.

CHANGELOG.next.asciidoc

@@ -69,6 +69,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Improve ECS field mappings in Sysmon module. `file.name`, `file.directory`, and `file.extension` are now populated. {issue}18364[18364]
 - Improve ECS field mappings in Sysmon module. `rule.name` is populated for all events when present. {issue}18364[18364]
 - Add Powershell module. Support for event ID's: `400`, `403`, `600`, `800`, `4103`, `4014`, `4105`, `4106`. {issue}16262[16262] {pull}18526[18526]
+- Fix Powershell processing of downgraded engine events. {pull}18966[18966]
 
 *Functionbeat*
 

x-pack/winlogbeat/module/powershell/_meta/kibana/7/dashboard/Powershell-Overview-Dashboard.json

@@ -2317,11 +2317,13 @@
       },
       {
         "attributes": {
-          "columns": [
+        "columns": [
+            "event.code",
+            "powershell.engine.version",
             "powershell.runspace_id",
-            "powershell.pipeline_id",
             "process.args",
-            "powershell.command.invocation_details"
+            "powershell.command.invocation_details",
+            "powershell.file.script_block_text"
           ],
           "description": "",
           "hits": 0,
@@ -2332,7 +2334,7 @@
               "indexRefName": "kibanaSavedObjectMeta.searchSourceJSON.index",
               "query": {
                 "language": "kuery",
-                "query": "(winlog.provider_name : \"PowerShell\" or winlog.provider_name : \"Microsoft-Windows-PowerShell\" ) and (process.args : * or powershell.command.invocation_details.related_command: * )"
+                "query": "(winlog.provider_name : \"PowerShell\" or winlog.provider_name : \"Microsoft-Windows-PowerShell\" )"
               },
               "version": true
             }

x-pack/winlogbeat/module/powershell/config/winlogbeat-powershell.js

@@ -84,8 +84,21 @@ var powershell = (function () {
         });
     };
 
+    // countChunksDelimitedBy will return the number of chunks contained in a field
+    // that are delimited by the given delimiter.
+    var countChunksDelimitedBy = function(evt, fromField, delimiter) {
+        var str = evt.Get(fromField);
+        if (!str) {
+            return 0;
+        }
+        return str.split(delimiter).length-1;
+    };
+
     var dissect4xxAnd600 = function (evt) {
-        dissectField("winlog.event_data.param3", "winlog.event_data", 15, "\t", "=").Run(evt);
+        var delimiter = "\t";
+        var chunks = countChunksDelimitedBy(evt, "winlog.event_data.param3", delimiter);
+
+        dissectField("winlog.event_data.param3", "winlog.event_data", chunks, delimiter, "=").Run(evt);
 
         // these fields contain redundant information.
         evt.Delete("winlog.event_data.param1");
@@ -94,15 +107,21 @@ var powershell = (function () {
     };
 
     var dissect800Detail = function (evt) {
-        dissectField("winlog.event_data.param2", "winlog.event_data", 13, "\t", "=").Run(evt);
+        var delimiter = "\t";
+        var chunks = countChunksDelimitedBy(evt, "winlog.event_data.param2", delimiter);
+
+        dissectField("winlog.event_data.param2", "winlog.event_data", chunks, "\t", "=").Run(evt);
 
         // these fields contain redundant information.
         evt.Delete("winlog.event_data.param1");
         evt.Delete("winlog.event_data.param2");
     };
 
     var dissect4103 = function (evt) {
-        dissectField("winlog.event_data.ContextInfo", "winlog.event_data", 16, "        ", " = ").Run(evt);
+        var delimiter = "        ";
+        var chunks = countChunksDelimitedBy(evt, "winlog.event_data.ContextInfo", delimiter);
+
+        dissectField("winlog.event_data.ContextInfo", "winlog.event_data", chunks, delimiter, " = ").Run(evt);
 
         // these fields contain redundant information.
         evt.Delete("winlog.event_data.ContextInfo");
@@ -170,7 +189,7 @@ var powershell = (function () {
     var addProcessArgs = function (evt) {
         splitCommandLine(evt, "process.command_line", "process.args");
         var args = evt.Get("process.args");
-        if (args.length > 0) {
+        if (args && args.length > 0) {
             evt.Put("process.args_count", args.length);
         }
     };

x-pack/winlogbeat/module/powershell/test/testdata/400.evtx.golden.json

@@ -171,5 +171,56 @@
       "record_id": 1579,
       "task": "Engine Lifecycle"
     }
+  },
+  {
+    "@timestamp": "2020-06-04T07:20:27.7472275Z",
+    "event": {
+      "action": "Engine Lifecycle",
+      "category": [
+        "process"
+      ],
+      "code": 400,
+      "kind": "event",
+      "module": "powershell",
+      "provider": "PowerShell",
+      "sequence": 9,
+      "type": [
+        "start"
+      ]
+    },
+    "host": {
+      "name": "vagrant"
+    },
+    "log": {
+      "level": "information"
+    },
+    "powershell": {
+      "engine": {
+        "new_state": "Available",
+        "previous_state": "None",
+        "version": "2.0"
+      },
+      "process": {
+        "executable_version": "2.0"
+      },
+      "runspace_id": "6ebeca05-d618-4c66-a0d8-4269d800d099"
+    },
+    "process": {
+      "entity_id": "7018c049-c75b-4e02-9c0f-6761b97e1657",
+      "title": "ConsoleHost"
+    },
+    "winlog": {
+      "api": "wineventlog",
+      "channel": "Windows PowerShell",
+      "computer_name": "vagrant",
+      "event_id": 400,
+      "keywords": [
+        "Classic"
+      ],
+      "opcode": "Info",
+      "provider_name": "PowerShell",
+      "record_id": 18591,
+      "task": "Engine Lifecycle"
+    }
   }
 ]

x-pack/winlogbeat/module/powershell/test/testdata/403.evtx.golden.json

@@ -175,5 +175,56 @@
       "record_id": 1766,
       "task": "Engine Lifecycle"
     }
+  },
+  {
+    "@timestamp": "2020-06-04T07:20:28.6861939Z",
+    "event": {
+      "action": "Engine Lifecycle",
+      "category": [
+        "process"
+      ],
+      "code": 403,
+      "kind": "event",
+      "module": "powershell",
+      "provider": "PowerShell",
+      "sequence": 10,
+      "type": [
+        "end"
+      ]
+    },
+    "host": {
+      "name": "vagrant"
+    },
+    "log": {
+      "level": "information"
+    },
+    "powershell": {
+      "engine": {
+        "new_state": "Stopped",
+        "previous_state": "Available",
+        "version": "2.0"
+      },
+      "process": {
+        "executable_version": "2.0"
+      },
+      "runspace_id": "6ebeca05-d618-4c66-a0d8-4269d800d099"
+    },
+    "process": {
+      "entity_id": "7018c049-c75b-4e02-9c0f-6761b97e1657",
+      "title": "ConsoleHost"
+    },
+    "winlog": {
+      "api": "wineventlog",
+      "channel": "Windows PowerShell",
+      "computer_name": "vagrant",
+      "event_id": 403,
+      "keywords": [
+        "Classic"
+      ],
+      "opcode": "Info",
+      "provider_name": "PowerShell",
+      "record_id": 18592,
+      "task": "Engine Lifecycle"
+    }
   }
 ]

x-pack/winlogbeat/module/powershell/test/testdata/600.evtx.golden.json

@@ -115,5 +115,54 @@
       "record_id": 1266,
       "task": "Provider Lifecycle"
     }
+  },
+  {
+    "@timestamp": "2020-06-04T07:25:04.8574302Z",
+    "event": {
+      "action": "Provider Lifecycle",
+      "category": [
+        "process"
+      ],
+      "code": 600,
+      "kind": "event",
+      "module": "powershell",
+      "provider": "PowerShell",
+      "sequence": 8,
+      "type": [
+        "info"
+      ]
+    },
+    "host": {
+      "name": "vagrant"
+    },
+    "log": {
+      "level": "information"
+    },
+    "powershell": {
+      "process": {
+        "executable_version": "2.0"
+      },
+      "provider": {
+        "name": "Certificate",
+        "new_state": "Started"
+      }
+    },
+    "process": {
+      "entity_id": "99a16837-7392-463d-afe5-5f3ed24bd358",
+      "title": "ConsoleHost"
+    },
+    "winlog": {
+      "api": "wineventlog",
+      "channel": "Windows PowerShell",
+      "computer_name": "vagrant",
+      "event_id": 600,
+      "keywords": [
+        "Classic"
+      ],
+      "opcode": "Info",
+      "provider_name": "PowerShell",
+      "record_id": 18640,
+      "task": "Provider Lifecycle"
+    }
   }
 ]