Linux Process Creation: ESXi esxcli system discovery via system namespace

Alert on esxcli system invocations using get/list subcommands to discover ESXi system component information.

FreeReviewedSigma · Medium · v3
Product
linux
Category
process_creation
Author
Cedric Maurugeon (SigmaHQ), DRL 1.1
Published
2023-09-04
Updated
2026-07-31
title: "Linux Process Creation: ESXi esxcli system discovery via system namespace"
id: ad05d9ec-5cff-4502-92ad-0a4ee977f64b
status: test
description: This rule matches Linux process creation events where an executable path ends with /esxcli and the command line contains the system flag. It further requires command-line text consistent with esxcli subcommands such as " get" or " list", indicating attempts to retrieve system component information (for example, accounts, modules, or NTP). Such discovery helps attackers enumerate the hypervisor environment before later actions, and the detection relies on process start telemetry including Image and CommandLine.
references:
  - https://www.crowdstrike.com/blog/hypervisor-jackpotting-ecrime-actors-increase-targeting-of-esxi-servers/
  - https://developer.broadcom.com/xapis/esxcli-command-reference/7.0.0/namespace/esxcli_system.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/linux/process_creation/proc_creation_lnx_esxcli_system_discovery.yml
author: Cedric Maurugeon, Huntrule Team
date: 2023-09-04
tags:
  - attack.discovery
  - attack.execution
  - attack.t1033
  - attack.t1007
  - attack.t1059.012
logsource:
  category: process_creation
  product: linux
detection:
  selection_img:
    Image|endswith: /esxcli
    CommandLine|contains: system
  selection_cli:
    CommandLine|contains:
      - " get"
      - " list"
  condition: all of selection_*
falsepositives:
  - Legitimate administration activities
level: medium
license: DRL-1.1
related:
  - id: e80273e1-9faf-40bc-bd85-dbaff104c4e9
    type: derived