Refactor

salt/elasticfleet/config.sls

@@ -75,14 +75,22 @@ eapackageupgrade:
 {%   if GLOBALS.role != "so-fleet" %}
 
 {% if not GLOBALS.airgap %}
+elasticdefendrepodir:
+  file.directory:
+    - name: /nsm/securityonion-resources
+    - user: 939
+    - group: 939
+    - makedirs: True
+
 soresourcesrepoclone:
   git.latest:
     - name: https://github.com/Security-Onion-Solutions/securityonion-resources.git
-    - target: /opt/so/saltstack/local/salt/elasticfleet/files/securityonion-resources
-    - rev: 'dev/defend-filters'
+    - target: /nsm/securityonion-resources
+    - rev: 'dev/defend_filters'
     - depth: 1
     - force_fetch: true
     - force_clone: true
+    - user: socore # id is not allowed for this 
 {% endif %}
 
 elasticdefendconfdir:
@@ -92,13 +100,6 @@ elasticdefendconfdir:
     - group: 939
     - makedirs: True
   
-elasticdefendrulesets:
-  file.recurse:
-    - name: /opt/so/conf/elastic-fleet/defend-exclusions/rulesets
-    - source: salt://elasticfleet/files/securityonion-resources/event-filters/
-    - user: 947
-    - group: 939
-
 elasticdefenddisabled:
   file.managed:
     - name: /opt/so/conf/elastic-fleet/defend-exclusions/disabled-filters.yaml
@@ -115,6 +116,17 @@ elasticdefendcustom:
     - group: 939
     - mode: 600
 
+  cronelasticdefendfilters:
+    cron.present:
+      - name: python3 /sbin/so-elastic-defend-manage-filters.py -c /opt/so/conf/elasticsearch/curl.config -d /opt/so/conf/elastic-fleet/defend-exclusions/disabled-filters.yaml -i /nsm/securityonion-resources/event_filters/ -i /opt/so/conf/elastic-fleet/defend-exclusions/rulesets/custom-filters/ &>> /opt/so/log/elasticfleet/elastic-defend-manage-filters.log
+      - identifier: elastic-defend-filters
+      - user: root
+      - minute: '0'
+      - hour: '3'
+      - daymonth: '*'
+      - month: '*'
+      - dayweek: '*'
+
 eaintegrationsdir:
   file.directory:
     - name: /opt/so/conf/elastic-fleet/integrations

salt/elasticfleet/defaults.yaml

@@ -8,6 +8,8 @@ elasticfleet:
       endpoints_enrollment: ''
       es_token: ''
       grid_enrollment: ''
+    defend_filters:
+      enable_auto_configuration: False
   logging:
     zeek:
       excluded:

salt/elasticfleet/files/soc/elastic-defend-custom-filters.yaml

@@ -1,27 +1,27 @@
 title: 'Template 1'
-id: '2B160E43-3B95-4B50-AA3F-25D99F51FA69'
-description: 'Credit @ITProPaul'
-references: 'https://github.com/Neo23x0/sysmon-config'
-author: 'SOS'
-date: '09/18/24'
-event_type: 'NetworkConnect'
+id: 'This needs to be a UUIDv4 id - https://www.uuidgenerator.net/version4'
+description: 'Short description detailing what this rule is filtering and why.'
+references: 'Relevant urls, etc'
+author: '@SecurityOnion'
+date: 'MM/DD/YY'
+event_type: 'dns_query'
 filter_type: 'exclude'
 filter:
   selection_1:
-    TargetField: 'DestinationIp'
-    Condition: 'begin with'
-    Pattern: 'fe80:0:0:0'
+    TargetField: 'QueryName'
+    Condition: 'end with'
+    Pattern: '.thawte.com'
 ---
-title: 'Template2'
-id: '3B160E43-3B95-4B50-AA3F-25D99F51FA69'
-description: 'Credit @ITProPaul'
-references: 'https://github.com/Neo23x0/sysmon-config'
-author: 'SOS'
-date: '09/18/24'
-event_type: 'NetworkConnect'
+title: 'Template 2'
+id: 'This needs to be a UUIDv4 id - https://www.uuidgenerator.net/version4'
+description: 'Short description detailing what this rule is filtering and why.'
+references: 'Relevant urls, etc'
+author: '@SecurityOnion'
+date: 'MM/DD/YY'
+event_type: 'process_creation'
 filter_type: 'exclude'
 filter:
   selection_1:
-    TargetField: 'DestinationIp'
-    Condition: 'begin with'
-    Pattern: 'fe80:0:0:0'
+    TargetField: 'ParentImage'
+    Condition: 'is'
+    Pattern: 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\ngentask.exe'

salt/elasticfleet/soc_elasticfleet.yaml

@@ -21,7 +21,7 @@ elasticfleet:
         advanced: True
       elastic-defend-custom-filters__yaml:
         title: Custom Elastic Defend filters
-        description: Enter custom filters.
+        description: Enter custom filters seperated by ---
         syntax: yaml
         file: True
         global: True

salt/elasticfleet/tools/sbin/so-elastic-defend-manage-filters.py

@@ -1,4 +1,4 @@
-import yaml
+from datetime import datetime
 import sys
 import getopt
 from so_elastic_defend_filters_helper import *
@@ -6,44 +6,51 @@ import logging
 
 logging.basicConfig(level=logging.INFO, format='%(message)s')
 
-# Define mappings for conditional_field, event_type, and conditions
-FIELD_MAPPINGS = {
+# Define mappings for Target Field, Event Type, Conditions
+TARGET_FIELD_MAPPINGS = {
     "Image": "process.executable",
     "ParentImage": "process.parent.executable",
     "CommandLine": "process.command_line",
     "ParentCommandLine": "process.parent.command_line",
+    "DestinationHostname": "destination.domain",
     "QueryName": "dns.question.name",
     "DestinationIp": "destination.ip",
-    "TargetObject": "registry.path"
+    "TargetObject": "registry.path",
+    "TargetFilename": "file.path"
 }
 
 DATASET_MAPPINGS = {
-    "ProcessCreate": "endpoint.events.process",
-    "NetworkConnect": "endpoint.events.network",
-    "FileCreate": "endpoint.events.file",
-    "RegistryEvent": "endpoint.events.registry",
-    "DnsQuery": "endpoint.events.network"
+    "process_create": "endpoint.events.process",
+    "network_connection": "endpoint.events.network",
+    "file_create": "endpoint.events.file",
+    "file_delete": "endpoint.events.file",
+    "registry_event": "endpoint.events.registry",
+    "dns_query": "endpoint.events.network"
 }
 
 CONDITION_MAPPINGS = {
     "is": ("included", "match"),
     "end with": ("included", "wildcard"),
     "begin with": ("included", "wildcard"),
-    "contains": ("included", "wildcard"),
-    "contains any": ("included", "match_any"),
-    "excluded": ("excluded", "match")
+    "contains": ("included", "wildcard")
 }
 
 # Extract entries for a rule
-def extract_entries(data):
+def extract_entries(data, event_type):
     entries = []
     filter_data = data.get('filter', {})
     for value in filter_data.values():
-        target_field = FIELD_MAPPINGS.get(value.get('TargetField', ''))
+        target_field = TARGET_FIELD_MAPPINGS.get(value.get('TargetField', ''))
         condition = value.get('Condition', '')
         pattern = value.get('Pattern', '')
 
-        operator, match_type = CONDITION_MAPPINGS.get(condition, ("included", "match"))
+        if condition not in CONDITION_MAPPINGS:
+            logging.error(f"Invalid condition: {condition}")
+
+        # Modify the pattern based on the condition
+        pattern = modify_pattern(condition, pattern)
+
+        operator, match_type = CONDITION_MAPPINGS[condition]
 
         entries.append({
             "field": target_field,
@@ -51,10 +58,23 @@ def extract_entries(data):
             "type": match_type,
             "value": pattern
         })
+
+    # Add the event.dataset entry from DATASET_MAPPINGS
+    dataset_value = DATASET_MAPPINGS.get(event_type, '')
+    if dataset_value:
+        entries.append({
+            "field": "event.dataset",
+            "operator": "included",
+            "type": "match",
+            "value": dataset_value
+        })
+    else:
+        logging.error(f"No dataset mapping found for event_type: {event_type}")
+
     return entries
 
-# Build the JSON entry
-def build_json_entry(data, entries, guid, event_type, dataset, context):
+# Build the JSON
+def build_json_entry(entries, guid, event_type, context):
     return {
         "comments": [],
         "entries": entries,
@@ -85,6 +105,26 @@ def disable_check(guid, disabled_rules, username, password):
         return True, "NOP"
     return False, None
 
+def modify_pattern(condition, pattern):
+    """
+    Modify the pattern based on the condition.
+    - 'end with': Add '*' to the beginning of the pattern.
+    - 'begin with': Add '*' to the end of the pattern.
+    - 'contains': Add '*' to both the beginning and end of the pattern.
+    """
+    if isinstance(pattern, list):
+        # Apply modification to each pattern in the list if it's a list of patterns
+        return [modify_pattern(condition, p) for p in pattern]
+    
+    if condition == "end with":
+        return f"*{pattern}"
+    elif condition == "begin with":
+        return f"{pattern}*"
+    elif condition == "contains":
+        return f"*{pattern}*"
+    return pattern
+
+
 def process_rule_update_or_create(guid, json_entry, username, password):
     existing_rule = api_request("GET", guid, username, password)
 
@@ -122,8 +162,8 @@ def process_rules(yaml_files, disabled_rules, username, password):
             continue
 
         # Extract entries and build JSON
-        entries = extract_entries(data)
-        json_entry = build_json_entry(data, entries, guid, event_type, dataset, context)
+        entries = extract_entries(data, event_type)
+        json_entry = build_json_entry(entries, guid, event_type, context)
 
         # Process rule creation or update
         status = process_rule_update_or_create(guid, json_entry, username, password)
@@ -167,6 +207,9 @@ def main(argv):
             flags = load_flags(arg)
             return main(argv + flags)
 
+    timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+    logging.info(f"\n{timestamp}")
+
     validate_inputs(credentials_file, disabled_file, yaml_directories)
 
     credentials = load_credentials(credentials_file)
@@ -200,6 +243,9 @@ def main(argv):
     logging.info(f"Rule status Summary")
     logging.info(f" - Active rules: {total_stats['rule_count'] - total_stats['disabled']}")
     logging.info(f" - Disabled rules: {total_stats['disabled']}")
+    timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+    logging.info(f"Execution completed at: {timestamp}")
+
 
 if __name__ == "__main__":
     main(sys.argv[1:])

salt/elasticfleet/tools/sbin/so_elastic_defend_filters_helper.py

@@ -7,19 +7,21 @@ import requests
 from requests.auth import HTTPBasicAuth
 import shutil
 
-# Extract only the 'entries' and 'description' fields
-def extract_relevant_fields(rule):
+# Extract 'entries', 'description' and 'os_types' fields
+def extract_relevant_fields(filter):
     return {
-        'entries': rule.get('entries', []),
-        'description': rule.get('description', '')
+        'entries': filter.get('entries', []),
+        'description': filter.get('description', '')
     }
 
-# Sort lists and recursively sort keys in dictionaries for consistency
+# Sort for consistency, so that a hash can be generated
 def sorted_data(value):
     if isinstance(value, dict):
+        # Recursively sort the dictionary by key
         return {k: sorted_data(v) for k, v in sorted(value.items())}
     elif isinstance(value, list):
-        return sorted(sorted_data(v) for v in value)
+        # Sort lists; for dictionaries, sort by a specific key
+        return sorted(value, key=lambda x: tuple(sorted(x.items())) if isinstance(x, dict) else x)
     return value
 
 # Generate a hash based on sorted relevant fields
@@ -109,6 +111,9 @@ def prepare_custom_rules(input_file, output_dir):
                 if 'id' not in doc:
                     print(f"Skipping rule, no 'id' found: {doc}")
                     continue
+                if doc.get('title') in ["Template 1", "Template 2"]:
+                    print(f"Skipping template rule with title: {doc['title']}")
+                    continue
                 # Create a filename using the 'id' field
                 file_name = os.path.join(output_dir, f"{doc['id']}.yaml")
                 
@@ -120,4 +125,4 @@ def prepare_custom_rules(input_file, output_dir):
     except yaml.YAMLError as e:
         print(f"Error parsing YAML: {e}")
     except Exception as e:
-        print(f"Error processing file: {e}")
+        print(f"Error processing file: {e}")