[New Rule] SIP Provider Modification (#891)

* Create defense_evasion_sip_provider_mod.toml

* add reference

rules/windows/defense_evasion_sip_provider_mod.toml

@@ -0,0 +1,54 @@
+[metadata]
+creation_date = "2021/01/20"
+maturity = "production"
+updated_date = "2021/01/20"
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies modifications to the registered Subject Interface Package (SIP) providers. SIP providers are used by the
+Windows cryptographic system to validate file signatures on the system. This may be an attempt to bypass signature
+validation checks or inject code into critical processes.
+"""
+from = "now-9m"
+index = ["winlogbeat-*", "logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License"
+name = "SIP Provider Modification"
+references = ["https://github.com/mattifestation/PoCSubjectInterfacePackage"]
+risk_score = 47
+rule_id = "f2c7b914-eda3-40c2-96ac-d23ef91776ca"
+severity = "medium"
+tags = ["Elastic", "Host", "Windows", "Threat Detection", "Defense Evasion"]
+type = "eql"
+
+query = '''
+registry where event.type:"change" and
+  registry.path: (
+    "HKLM\\SOFTWARE\\Microsoft\\Cryptography\\OID\\EncodingType 0\\CryptSIPDllPutSignedDataMsg\\{*}\\Dll",
+    "HKLM\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\OID\\EncodingType 0\\CryptSIPDllPutSignedDataMsg\\{*}\\Dll",
+    "HKLM\\SOFTWARE\\Microsoft\\Cryptography\\Providers\\Trust\\FinalPolicy\\{*}\\$Dll",
+    "HKLM\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\Providers\\Trust\\FinalPolicy\\{*}\\$Dll"
+    ) and
+  registry.data.strings:"*.dll"
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1553"
+name = "Subvert Trust Controls"
+reference = "https://attack.mitre.org/techniques/T1553/"
+[[rule.threat.technique.subtechnique]]
+id = "T1553.003"
+name = "SIP and Trust Provider Hijacking"
+reference = "https://attack.mitre.org/techniques/T1553/003/"
+
+
+
+[rule.threat.tactic]
+id = "TA0005"
+name = "Defense Evasion"
+reference = "https://attack.mitre.org/tactics/TA0005/"
+