Sync RTA Suspicious Echo Execution (#4110)

Co-authored-by: shashank-elastic <[email protected]>

(cherry picked from commit e664679)

rta/linux_persistence_suspicious_echo_execution.py

@@ -0,0 +1,40 @@
+# Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+# or more contributor license agreements. Licensed under the Elastic License
+# 2.0; you may not use this file except in compliance with the Elastic License
+# 2.0.
+
+import sys
+
+from . import RtaMetadata, common
+
+metadata = RtaMetadata(
+    uuid="a2217fc5-7105-4457-98fe-1cd5f810dc1a",
+    platforms=["linux"],
+    endpoint=[
+        {
+            "rule_name": "Suspicious Echo Execution",
+            "rule_id": "a13c8f01-36a5-4ad7-a282-8d297cf62860",
+        },
+    ],
+    techniques=["T1543", "T1053", "T1037", "T1546"],
+)
+
+
+@common.requires_os(*metadata.platforms)
+def main() -> None:
+    common.log("Creating a fake executable..")
+    masquerade = "/tmp/sh"
+    source = common.get_path("bin", "linux.ditto_and_spawn")
+    common.copy_file(source, masquerade)
+    common.log("Granting execute permissions...")
+    common.execute(["chmod", "+x", masquerade])
+
+    commands = [masquerade, "-c", "echo /dev/tcp/foo"]
+    common.execute([*commands], timeout=5, kill=True)
+    common.log("Cleaning...")
+    common.remove_file(masquerade)
+    common.log("Simulation successfull!")
+
+
+if __name__ == "__main__":
+    sys.exit(main())