Detection: Cisco Isovalent - Shell Execution

Updated Date: 2026-01-05 ID: 12345678-abcd-1234-ef00-1234567890ab Author: Bhavin Patel, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects the execution of a shell inside a container namespace within the Cisco Isovalent environment. It identifies this activity by monitoring process execution logs for the execution of a shell (sh or bash) inside a container namespace. This behavior is significant for a SOC as it could allow an attacker to gain shell access to the container, potentially leading to further compromise of the Kubernetes cluster. If confirmed malicious, this activity could lead to data theft, service disruption, privilege escalation, lateral movement, and further attacks, severely compromising the cluster's security and integrity.

Search

1`cisco_isovalent_process_exec` process_name IN ("sh", "ksh", "zsh", "bash", "dash", "rbash", "fish", "csh", "tcsh", "ion", "eshell")
2
3| stats count by cluster_name parent_process_name process_name process_exec process_id node_name 
4| `cisco_isovalent___shell_execution_filter`

Data Source

Name	Platform	Sourcetype	Source
Cisco Isovalent Process Exec	Other	`'cisco:isovalent:processExec'`	`'not_applicable'`

Macros Used

Name	Value
cisco_isovalent_process_exec	`sourcetype=cisco:isovalent:processExec`
cisco_isovalent___shell_execution_filter	`search *`

cisco_isovalent___shell_execution_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1543	Create or Modify System Process	Persistence

Exploitation

Installation

DE.AE

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

The detection is based on process execution data generated by Cisco Isovalent Runtime Security. Ensure that Isovalent Runtime Security is deployed and configured in your Kubernetes environment to emit process_exec events. Configure the Cisco Security Cloud TA to collect these logs via HTTP Event Collector (HEC) and normalize them into the Splunk Common Information Model. This integration ensures that all relevant pod, container, and process activity is captured for monitoring and detection of suspicious behavior.

Known False Positives

This activity may be triggered by legitimate administrative scripts, container images, or third-party operators that use cron for scheduled tasks, so please investigate the alert in context to rule out benign operations.

Associated Analytic Story

Cisco Isovalent Suspicious Activity

Risk Based Analytics (RBA)

Risk Message:

The shell [$process_name$] was executed on container pod namespace [$node_name$]

Risk Object	Risk Object Type	Risk Score	Threat Objects
node_name	system	49	process_name

References

https://www.sysdig.com/blog/mitre-attck-framework-for-container-runtime-security-with-sysdig-falco

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`not_applicable`	`cisco:isovalent:processExec`
Integration	✅ Passing	Dataset	`not_applicable`	`cisco:isovalent:processExec`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1