Name:Kubernetes Anomalous Traffic on Network Edge id:886c7e51-2ea1-425d-8705-faaca5a64cc6 version:3 date:2024-10-17 author:Matthew Moore, Splunk status:experimental type:Anomaly Description:The following analytic identifies anomalous network traffic volumes between Kubernetes workloads or between a workload and external sources. It leverages Network Performance Monitoring metrics collected via an OTEL collector and pulled from Splunk Observability Cloud. The detection compares recent network metrics (tcp.bytes, tcp.new_sockets, tcp.packets, udp.bytes, udp.packets) over the last hour with the average over the past 30 days to identify significant deviations. This activity is significant as unexpected spikes may indicate unauthorized data transfers or lateral movement. If confirmed malicious, it could lead to data exfiltration or compromise of additional services, potentially resulting in data breaches. Data_source:
search:| mstats avg(tcp.*) as tcp.* avg(udp.*) as udp.* where `kubernetes_metrics` AND earliest=-1h by k8s.cluster.name source.workload.name dest.workload.name span=10s | eval key='source.workload.name' + ":" + 'dest.workload.name' | join type=left key [ mstats avg(tcp.*) as avg_tcp.* avg(udp.*) as avg_udp.* stdev(tcp.*) as stdev_tcp.* avg(udp.*) as stdev_udp.* where `kubernetes_metrics` AND earliest=-30d latest=-1h by source.workload.name dest.workload.name | eval key='source.workload.name' + ":" + 'dest.workload.name' ] | eval anomalies = "" | foreach stdev_* [ eval anomalies =if( '<<MATCHSTR>>' > ('avg_<<MATCHSTR>>' + 3 * 'stdev_<<MATCHSTR>>'), anomalies + "<<MATCHSTR>> higher than average by " + tostring(round(('<<MATCHSTR>>' - 'avg_<<MATCHSTR>>')/'stdev_<<MATCHSTR>>' ,2)) + " Standard Deviations. <<MATCHSTR>>=" + tostring('<<MATCHSTR>>') + " avg_<<MATCHSTR>>=" + tostring('avg_<<MATCHSTR>>') + " 'stdev_<<MATCHSTR>>'=" + tostring('stdev_<<MATCHSTR>>') + ", " , anomalies) ] | fillnull | eval anomalies = split(replace(anomalies, ",\s$$$$", "") ,", ") | where anomalies!="" | stats count(anomalies) as count values(anomalies) as anomalies by k8s.cluster.name source.workload.name dest.workload.name | rename service as k8s.service | where count > 5 | rename k8s.cluster.name as host | `kubernetes_anomalous_traffic_on_network_edge_filter`
how_to_implement:To gather NPM metrics the Open Telemetry to the Kubernetes Cluster and enable Network Performance Monitoring according to instructions found in Splunk Docs https://docs.splunk.com/observability/en/infrastructure/network-explorer/network-explorer-setup.html#network-explorer-setup In order to access those metrics from within Splunk Enterprise and ES, the Splunk Infrastructure Monitoring add-on must be installed and configured on a Splunk Search Head. Once installed, first configure the add-on with your O11y Cloud Org ID and Access Token. Lastly set up the add-on to ingest metrics from O11y cloud using the following settings, and any other settings left at default:
* Name sim_npm_metrics_to_metrics_index
* Metric Resolution 10000 known_false_positives:unknown References: -https://github.com/signalfx/splunk-otel-collector-chart drilldown_searches:
: tags: analytic_story: - 'Abnormal Kubernetes Behavior using Splunk Infrastructure Monitoring' asset_type:Kubernetes confidence:50 impact:50 message:Kubernetes Anomalous Traffic on Network Edge in kubernetes cluster $host$ mitre_attack_id: - 'T1204' observable: name:'host' type:'Hostname' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - 'tcp.*' - 'udp.*' - 'k8s.cluster.name' - 'source.workload.name' - 'dest.workload.name' - 'udp.packets' risk_score:25 security_domain:network
