Detection rules › Sigma
Audio Capture
Detects attempts to record audio using the arecord and ecasound utilities.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Collection |
Telemetry coverage
Rule body
title: Audio Capture
id: a7af2487-9c2f-42e4-9bb9-ff961f0561d5
status: test
description: Detects attempts to record audio using the arecord and ecasound utilities.
references:
- https://linux.die.net/man/1/arecord
- https://linuxconfig.org/how-to-test-microphone-with-audio-linux-sound-architecture-alsa
- https://manpages.debian.org/unstable/ecasound/ecasound.1.en.html
- https://ecasound.seul.org/ecasound/Documentation/examples.html#fconversions
author: Pawel Mazur, Milad Cheraghi
date: 2021-09-04
modified: 2025-12-05
tags:
- attack.collection
- attack.t1123
logsource:
product: linux
service: auditd
detection:
selection_execve:
type: EXECVE
a0: arecord
a1: '-vv'
a2: '-fdat'
selection_syscall_memfd_create:
type: SYSCALL
exe|endswith: "/ecasound"
SYSCALL: 'memfd_create'
condition: 1 of selection_*
falsepositives:
- Unknown
level: low
Stages and Predicates
Stage 0: condition
1 of selection_*Stage 1: selection_execve
selection_execve:
type: EXECVE
a0: arecord
a1: '-vv'
a2: '-fdat'
Stage 2: selection_syscall_memfd_create
selection_syscall_memfd_create:
type: SYSCALL
exe|endswith: "/ecasound"
SYSCALL: 'memfd_create'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
SYSCALL | eq |
| field:"SYSCALL" kind:eq value:"memfd_create" |
a0 | eq |
| field:"a0" kind:eq value:"arecord" |
a1 | eq |
| field:"a1" kind:eq value:"-vv" |
a2 | eq |
| field:"a2" kind:eq value:"-fdat" |
exe | ends_with |
| field:"exe" kind:ends_with value:"/ecasound" |
type | eq |
| field:"type" kind:eq |