Lowercase msg before matching

core/lib/rules.py

@@ -81,7 +81,7 @@ def process_rules(data):
                     if field == "msg":
                         for msg in value:
                             if "msg" in message:
-                                if msg in message["msg"]:
+                                if msg.lower() in message["msg"].lower():
                                     matched_field_number += 1
                                     matched_fields.append(field)
                                     # Break out of the msg matching loop