Added Sigma Rules

rules/Sigma/win_exploit_systemnightmare.yml

@@ -0,0 +1,30 @@
+title: SystemNightmare Exploitation Script Execution
+author: Florian Roth
+date: 2021/08/11
+description: Detects the exploitation of PrinterNightmare to get a shell as LOCAL_SYSTEM
+detection:
+    SELECTION_1:
+        EventID: 1
+    SELECTION_2:
+        CommandLine: '*printnightmare.gentilkiwi.com*'
+    SELECTION_3:
+        CommandLine: '* /user:gentilguest *'
+    SELECTION_4:
+        CommandLine: '*Kiwi Legit Printer*'
+    condition: (SELECTION_1 and (SELECTION_2 or SELECTION_3 or SELECTION_4))
+falsepositives:
+- Unknown
+id: c01f7bd6-0c1d-47aa-9c61-187b91273a16
+level: critical
+logsource:
+    category: process_creation
+    product: windows
+references:
+- https://github.com/GossiTheDog/SystemNightmare
+status: experimental
+tags:
+- attack.privilege_escalation
+- attack.t1068
+yml_filename: win_exploit_systemnightmare.yml
+yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/process_creation
+