[New Rule] Remote Execution via File Shares (#455)

* [New Rule] Remote Execution via File Shares

* removed timeline_id

* fixed tags

* added extension to reduce response time

* Update rules/windows/lateral_movement_execution_via_file_shares_sequence.toml

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>

* ecs_version

* Update rules/windows/lateral_movement_execution_via_file_shares_sequence.toml

Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>

Co-authored-by: Justin Ibarra <brokensound77@users.noreply.github.com>
Co-authored-by: Brent Murphy <56412096+bm11100@users.noreply.github.com>

rules/windows/lateral_movement_execution_via_file_shares_sequence.toml

@@ -0,0 +1,42 @@
+[metadata]
+creation_date = "2020/11/03"
+maturity = "production"
+updated_date = "2020/11/03"
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies the execution of a file that was created by the virtual system process. This may indicate lateral movement
+via network file shares.
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.*", "winlogbeat-*"]
+language = "eql"
+license = "Elastic License"
+name = "Remote Execution via File Shares"
+references = ["https://blog.menasec.net/2020/08/new-trick-to-detect-lateral-movement.html"]
+risk_score = 47
+rule_id = "ab75c24b-2502-43a0-bf7c-e60e662c811e"
+severity = "medium"
+tags = ["Elastic", "Host", "Windows", "Threat Detection", "Lateral Movement"]
+type = "eql"
+
+query = '''
+sequence with maxspan=1m
+  [file where event.type in ("creation", "change") and process.pid == 4 and file.extension : "exe"] by host.id, file.path
+  [process where event.type in ("start", "process_started")] by host.id, process.executable
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1077"
+name = "Windows Admin Shares"
+reference = "https://attack.mitre.org/techniques/T1077/"
+
+
+[rule.threat.tactic]
+id = "TA0008"
+name = "Lateral Movement"
+reference = "https://attack.mitre.org/tactics/TA0008/"