adding event on triggering this rule

Signed-off-by: h4l0gen <[email protected]>

commits squashed

Signed-off-by: h4l0gen <[email protected]>

events/syscall/contact_ec2_instance_metadata_from_container.go

@@ -0,0 +1,53 @@
+//go:build linux
+// +build linux
+
+// 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 (
+	"github.com/falcosecurity/event-generator/events"
+	"os/exec"
+)
+
+var _ = events.Register(
+	ContactEC2InstanceMetadataServiceFromContainer,
+	events.WithDisabled(), // this rule is not included in falco_rules.yaml (stable rules), so disable the action
+)
+
+func ContactEC2InstanceMetadataServiceFromContainer(h events.Helper) error {
+	if h.InContainer() {
+		path, err := exec.LookPath("nc")
+		if err != nil {
+			// If we don't have an netcat, just bail
+			return &events.ErrSkipped{
+				Reason: "netcat utility not found in path",
+			}
+		}
+		// The IP address 169.254.169.254 is reserved for the Cloud Instance Metadata Service,
+		// a common endpoint used by cloud instances (GCP, AWS and Azure) to access
+		// metadata about the instance itself. Detecting attempts to communicate with this
+		// IP address from a container can indicate potential unauthorized access to
+		// sensitive cloud infrastructure metadata.
+
+		cmd := exec.Command("timeout", "1s", path, "169.254.169.254", "80")
+
+		if err := cmd.Run(); err != nil {
+			return err
+		}
+	}
+	return &events.ErrSkipped{
+		Reason: "'Contact EC2 Instance Metadata Service From Container' is applicable only to containers.",
+	}
+}