add win_pc_susp_rundll32_script_run

rules/windows/process_creation/win_pc_susp_rundll32_script_run.yml

@@ -0,0 +1,28 @@
+title: Suspicious Rundll32 Script in CommandLine
+id: 73fcad2e-ff14-4c38-b11d-4172c8ac86c7
+status: experimental
+description: Detects suspicious process related to rundll32 based on arguments
+author: frack113
+references:
+  - https://gist.github.com/ryhanson/227229866af52e2d963cf941af135a52
+  - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.011/T1218.011.md
+date: 2021/12/04
+logsource:
+  category: process_creation
+  product: windows
+detection:
+  selection_run:
+    CommandLine|contains|all:
+      - rundll32
+      - 'mshtml,RunHTMLApplication'
+  selection_script:
+    CommandLine|contains:
+      - 'javascript:'
+      - 'vbscript:'
+  condition: all of selection_*
+falsepositives:
+  - False positives depend on scripts and administrative tools used in the monitored environment
+level: medium
+tags:
+  - attack.defense_evasion
+  - attack.t1218.011