Detection rules › Sigma

macOS ESF Suspicious Process Execution

Status
experimental
Severity
medium
Log source
product macos, category process_creation, service endpointsecurity
Author
Eric Brown - Nebulock, Inc.
Source
github.com/Nebulock-Inc/macos-coresigma

Detects suspicious process execution patterns commonly used in malware and attacks

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique
Command & ControlNo specific technique

Event coverage

ProviderEventTitle
ESFexecProcess Execution (Notify)

Rule body yaml

title: macOS ESF Suspicious Process Execution
id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
status: experimental
description: Detects suspicious process execution patterns commonly used in malware and attacks
author: Eric Brown - Nebulock, Inc.
date: 2025/01/15
modified: 2025/01/15
logsource:
    product: macos
    service: endpointsecurity
    category: process_creation
detection:
    selection:
        esf.event_type: 9
        event.action: exec
        Image|contains:
            - '/tmp/'
            - '/var/tmp/'
            - '/dev/shm/'
        CommandLine|contains:
            - 'curl'
            - 'wget'
            - 'bash -c'
            - 'python -c'
            - '/bin/sh'
    condition: selection
falsepositives:
    - Legitimate system scripts and automation tools
level: medium
tags:
    - attack.execution
    - attack.command_and_control

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    esf.event_type: 9
    event.action: exec
    Image|contains:
        - '/tmp/'
        - '/var/tmp/'
        - '/dev/shm/'
    CommandLine|contains:
        - 'curl'
        - 'wget'
        - 'bash -c'
        - 'python -c'
        - '/bin/sh'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • /bin/sh
  • bash -c
  • curl
  • python -c
  • wget
Imagematch
  • /dev/shm/
  • /tmp/
  • /var/tmp/
esf.event_typeeq
  • 9
event.actioneq
  • exec