Added an event for default rule Container drift detected using chmod

Signed-off-by: GLVS Kiriti <glvskiriti2003369@gmail.com>

events/syscall/container_drift_detected_chmod.go

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+Copyright (C) 2024 The Falco Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package syscall
+
+import (
+	"os"
+	"os/exec"
+
+	"github.com/falcosecurity/event-generator/events"
+)
+
+var _ = events.Register(
+	ContainerDriftDetcted,
+	events.WithDisabled(), // this rules is not included in falco_rules.yaml (stable rules), so disable the action
+)
+
+func ContainerDriftDetcted(h events.Helper) error {
+	if h.InContainer() {
+		// Shell script content
+		scriptContent := `#!/bin/bash
+		echo "Hello World"
+		`
+
+		scriptFileName := "temp_script.sh"
+		if err := os.WriteFile(scriptFileName, []byte(scriptContent), 0755); err != nil {
+			h.Log().WithError(err).Error("Error writing script file")
+			return err
+		}
+		defer os.Remove(scriptFileName) // Remove file after function return
+
+		// Set execute permission on script file
+		if err := os.Chmod(scriptFileName, 0755); err != nil {
+			h.Log().WithError(err).Error("Error setting execute permission on script file")
+			return err
+		}
+
+		// Execute script file with its full path
+		cmd := exec.Command("./" + scriptFileName)
+		if err := cmd.Run(); err != nil {
+			h.Log().WithError(err).Error("Error running script file")
+			return err
+		}
+	}
+	return nil
+}