[New Rule] Potential Password Spraying Attack via SSH (#5515)

* [New Rule] Potential Password Spraying Attack via SSH

* ++

* Update rules/linux/credential_access_potential_password_spraying_attack.toml

Co-authored-by: Jonhnathan <26856693+w0rk3r@users.noreply.github.com>

* Update credential_access_potential_password_spraying_attack.toml

* Update credential_access_potential_password_spraying_attack.toml

* Change time bucket duration from 1 to 5 minutes

---------

Co-authored-by: Jonhnathan <26856693+w0rk3r@users.noreply.github.com>

rules/linux/credential_access_potential_password_spraying_attack.toml

@@ -0,0 +1,96 @@
+[metadata]
+creation_date = "2025/12/24"
+integration = ["system"]
+maturity = "production"
+updated_date = "2025/12/24"
+
+[rule]
+author = ["Elastic"]
+description = """
+This rule detects potential password spraying attacks via SSH by identifying multiple failed login
+attempts from a single source IP address targeting various user accounts within a short time frame.
+Password spraying is a technique where an attacker attempts to gain unauthorized access by trying a
+few commonly used passwords against many different accounts, rather than targeting a single account
+with multiple password attempts.
+"""
+from = "now-9m"
+language = "esql"
+license = "Elastic License v2"
+name = "Potential Password Spraying Attack via SSH"
+risk_score = 21
+rule_id = "9e81b1fd-e9fb-49a7-8ebe-0d1a14090142"
+severity = "low"
+tags = [
+    "Domain: Endpoint",
+    "OS: Linux",
+    "Use Case: Threat Detection",
+    "Tactic: Credential Access",
+]
+timestamp_override = "event.ingested"
+type = "esql"
+query = '''
+from logs-system.auth-* metadata _id, _index, _version
+
+// Create 5-minute time buckets
+| eval Esql.time_window_date_trunc = date_trunc(5 minutes, @timestamp)
+
+// Ensure event.action values in a list are expanded
+| mv_expand event.action 
+
+| where
+  event.category == "authentication" and event.action in ("ssh_login", "user_login") and event.outcome == "failure" and
+  source.ip is not null 
+
+// Keep relevant fields
+| keep
+   @timestamp,
+   _id,
+   _index,
+   _version,
+   event.category,
+   event.action,
+   event.outcome,
+   source.ip,
+   process.name,
+   user.name,
+   event.dataset,
+   data_stream.namespace,
+   agent.id,
+   user.id,
+   Esql.time_window_date_trunc
+
+| stats
+  Esql.event_count = count(*),
+  Esql.user_name_count_distinct = count_distinct(user.name),
+  Esql.user_name_values = values(user.name),
+  Esql.process_name_values = values(process.name),
+  Esql.event_dataset_values = values(event.dataset),
+  Esql.data_stream_namespace_values = values(data_stream.namespace)
+
+  by Esql.time_window_date_trunc, source.ip
+
+| where Esql.user_name_count_distinct > 10 and Esql.event_count >= 30
+'''
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1110"
+name = "Brute Force"
+reference = "https://attack.mitre.org/techniques/T1110/"
+
+[[rule.threat.technique.subtechnique]]
+id = "T1110.001"
+name = "Password Guessing"
+reference = "https://attack.mitre.org/techniques/T1110/001/"
+
+[[rule.threat.technique.subtechnique]]
+id = "T1110.003"
+name = "Password Spraying"
+reference = "https://attack.mitre.org/techniques/T1110/003/"
+
+[rule.threat.tactic]
+id = "TA0006"
+name = "Credential Access"
+reference = "https://attack.mitre.org/tactics/TA0006/"