Name:ESXi Shell Access Enabled id:15e79d0a-c659-42fd-9668-94108528f2ec version:1 date:2025-05-12 author:Raven Tait, Splunk status:production type:TTP Description:This detection identifies when the ESXi Shell is enabled on a host, which may indicate that a malicious actor is preparing to execute commands locally or establish persistent access. Enabling the shell outside of approved maintenance windows can be a sign of compromise or unauthorized administrative activity. Data_source:
-VMWare ESXi Syslog
search:`esxi_syslog` Message="*ESXi Shell*" Message="*has been enabled*" | rex field=_raw "'(?<user>\w+)@" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest user Message | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_shell_access_enabled_filter`
how_to_implement:This is based on syslog data generated by VMware ESXi hosts. To implement this search, you must configure your ESXi systems to forward syslog output to your Splunk deployment. These logs must be ingested with the appropriate Splunk Technology Add-on for VMware ESXi Logs, which provides field extractions and CIM compatibility. known_false_positives:Limited false positives in most environments, however tune as needed. Some Administrators may enable this for troubleshooting. References: drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") 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: - 'ESXi Post Compromise' - 'Black Basta Ransomware' asset_type:Infrastructure mitre_attack_id: - 'T1021' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' security_domain:endpoint
