Name:Kubernetes Falco Shell Spawned id:d2feef92-d54a-4a19-8306-b47c6ceba5b2 version:3 date:2024-09-30 author:Patrick Bareiss, Splunk status:production type:Anomaly Description:The following analytic detects instances where a shell is spawned within a Kubernetes container. Leveraging Falco, a cloud-native runtime security tool, this analytic monitors system calls within the Kubernetes environment and flags when a shell is spawned. This activity is significant for a SOC as it may indicate unauthorized access, allowing an attacker to execute arbitrary commands, manipulate container processes, or escalate privileges. If confirmed malicious, this could lead to data breaches, service disruptions, or unauthorized access to sensitive information, severely impacting the Kubernetes infrastructure's integrity and security. Data_source:
-Kubernetes Falco
search:`kube_container_falco` "A shell was spawned in a container" | fillnull | stats count by container_image container_image_tag container_name parent proc_exepath process user | `kubernetes_falco_shell_spawned_filter`
how_to_implement:The detection is based on data that originates from Kubernetes Audit logs. Ensure that audit logging is enabled in your Kubernetes cluster. Kubernetes audit logs provide a record of the requests made to the Kubernetes API server, which is crucial for monitoring and detecting suspicious activities. Configure the audit policy in Kubernetes to determine what kind of activities are logged. This is done by creating an Audit Policy and providing it to the API server. Use the Splunk OpenTelemetry Collector for Kubernetes to collect the logs. This doc will describe how to collect the audit log file https://github.com/signalfx/splunk-otel-collector-chart/blob/main/docs/migration-from-sck.md. When you want to use this detection with AWS EKS, you need to enable EKS control plane logging https://docs.aws.amazon.com/eks/latest/userguide/control-plane-logs.html. Then you can collect the logs from Cloudwatch using the AWS TA https://splunk.github.io/splunk-add-on-for-amazon-web-services/CloudWatchLogs/. known_false_positives:unknown References: -https://kubernetes.io/docs/tasks/debug/debug-cluster/audit/ drilldown_searches: name:'View the detection results for - "$user$"' search:'%original_detection_search% | search user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Kubernetes Security' asset_type:Kubernetes confidence:70 impact:70 message:A shell is spawned in the container $container_name$ by user $user$. mitre_attack_id: - 'T1204' observable: name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'container_image' - 'container_image_tag' - 'container_name' - 'parent' - 'proc_exepath' - 'process' - 'user' risk_score:49 security_domain:network
