Create EffluenceWebshell.yaml (#733)

EffluenceWebshell detection still to add specific process name ...

content/exchange/artifacts/EffluenceWebshell.yaml

@@ -0,0 +1,61 @@
+name: Windows.Detection.EffluenceWebshell
+author: Matt Green - @mgreen27
+description: |
+  This artifact detects Effluence Webshell observed deployed during exploitation 
+  of Atlassian Confluence CVE-2023-22515.
+
+reference:
+    - https://www.aon.com/cyber-solutions/aon_cyber_labs/detecting-effluence-an-unauthenticated-confluence-web-shell/
+
+type: CLIENT
+
+parameters:
+  - name: ProcessRegex
+    default: .
+    type: regex
+  - name: PidRegex
+    default: .
+    type: regex
+  - name: YaraRule
+    type: yara
+    default: |
+      rule ConfluencePageIndicator {
+        meta:
+            description = "Detects strings indicative of a web shell in Confluence page"
+            author = "Stroz Friedberg"
+            date = "2023-11-06"
+    
+        strings:
+            $confluence_title = "<title> - Confluence</title>" ascii wide
+            $hide_plugin_function = "hidePlugin(" ascii wide
+            $system_plugin_key = "ALWAYS_SYSTEM_PLUGIN_KEYS" ascii wide
+            $dashes = " ----- " ascii wide
+    
+        condition:
+            $confluence_title and $hide_plugin_function and $dashes and $system_plugin_key
+      }
+  - name: NumberOfHits
+    description: THis artifact will stop by default at one hit. This setting allows additional hits
+    default: 1
+    type: int
+  - name: ContextBytes
+    description: Include this amount of bytes around hit as context.
+    default: 0
+    type: int64
+
+
+sources:
+  - precondition:
+      SELECT OS From info() where OS = 'windows'
+
+    query: |
+      SELECT * FROM Artifact.Windows.Detection.Yara.Process(
+                            ProcessRegex=ProcessRegex,
+                            PidRegex=PidRegex,
+                            YaraRule=YaraRule,
+                            NumberOfHits=NumberOfHits,
+                            ContextBytes=ContextBytes )
+                            
+column_types:
+  - name: HitContext
+    type: preview_upload