ESXi Storage Information Discovery Via ESXCLI — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems), Cedric Maurugeon. Source status: test; severity: medium. Source dates: 2023-09-04 / not supplied.

{
  "category": "process_creation",
  "product": "linux"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: fba45d486c957ceadafafbe4c9088b7419d130755e4bb4a34353eff8b14ecc74

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: ESXi Storage Information Discovery Via ESXCLI
id: f41dada5-3f56-4232-8503-3fb7f9cf2d60
status: test
description: Detects execution of the "esxcli" command with the "storage" flag in order to retrieve information about the storage status and other related information. Seen used by malware such as DarkSide and LockBit.
references:
    - https://www.trendmicro.com/en_us/research/21/e/darkside-linux-vms-targeted.html
    - https://www.trendmicro.com/en_us/research/22/a/analysis-and-Impact-of-lockbit-ransomwares-first-linux-and-vmware-esxi-variant.html
    - https://developer.broadcom.com/xapis/esxcli-command-reference/7.0.0/namespace/esxcli_storage.html
author: Nasreddine Bencherchali (Nextron Systems), Cedric Maurugeon
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: 'storage'
    selection_cli:
        CommandLine|contains:
            - ' get'
            - ' list'
    condition: all of selection_*
falsepositives:
    - Legitimate administration activities
# Note: level can be reduced to low in some envs
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate administration activities

Source references

• https://www.trendmicro.com/en_us/research/21/e/darkside-linux-vms-targeted.html
• https://www.trendmicro.com/en_us/research/22/a/analysis-and-Impact-of-lockbit-ransomwares-first-linux-and-vmware-esxi-variant.html
• https://developer.broadcom.com/xapis/esxcli-command-reference/7.0.0/namespace/esxcli_storage.html