Audio Capture T1123

Tactic: Collection

An adversary can leverage a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information.

Events covered

10 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 11 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (21 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
CommandLine2contains 2/file, get-audiodevice , set-audiodevice , toggle-audiodevice
event.category2eq 2process
EventType1in 1exec, exec_event, start
Image1ends_with 1\soundrecorder.exe
ObjectName1contains 1\software\microsoft\windows\currentversion\capabilityacce..., \software\microsoft\windows\currentversion\capabilityacce...
SYSCALL1eq 1memfd_create
ScriptBlockText1eq 1, in 1get-audiodevice, get-microphoneaudio, mcisendstring
TargetObject1contains 1:#$recycle.bin#, :#temp#, :#users#default#
a01eq 1arecord
a11eq 1-vv
a21eq 1-fdat
camera1eq 1*
event.type1eq 1start
exe1ends_with 1/ecasound
host.os.type1eq 1

Top indicator values (55 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
event.categoryeq
process
2128
CommandLinecontains
/file
12
CommandLinecontains
get-audiodevice
1
CommandLinecontains
set-audiodevice
1
CommandLinecontains
toggle-audiodevice
1
CommandLinecontains
windowsaudiodevice-powershell-cmdlet
1
CommandLinecontains
write-audiodevice
1
EventTypein
exec
1171
EventTypein
exec_event
1139
EventTypein
start
1134
Imageends_with
\soundrecorder.exe
1
ObjectNamecontains
\software\microsoft\windows\currentversion\capabilityaccessmanager\consentsto...
1
ObjectNamecontains
\software\microsoft\windows\currentversion\capabilityaccessmanager\consentsto...
1
SYSCALLeq
memfd_create
1
ScriptBlockTexteq
get-audiodevice
1
ScriptBlockTexteq
get-microphoneaudio
1
ScriptBlockTexteq
recording
1
ScriptBlockTexteq
set-audiodevice
1
ScriptBlockTexteq
windowsaudiodevice-powershell-cmdlet
1
ScriptBlockTexteq
winmm.dll
1
ScriptBlockTextin
mcisendstring
1
ScriptBlockTextin
mcisendstringa
1
ScriptBlockTextin
mcisendstringw
1
ScriptBlockTextin
waveingetnumdevs
1
ScriptBlockTextin
waveinopen
1
ScriptBlockTextin
waveinstart
1
TargetObjectcontains
:#$recycle.bin#
1
TargetObjectcontains
:#temp#
1
TargetObjectcontains
:#users#default#
1
TargetObjectcontains
:#users#desktop#
1

Exclusions (11 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.

FieldKindValueRules excluding
cameracontains
facetime
3
cameracontains
iphone
3
cameracontains
macbook
3
microphonecontains
macbook pro microphone
3
speakercontains
airpods
3
ScriptBlockTexteq
powersploitindicators
1
ScriptBlockTexteq
sentinelbreakpoints
1
ScriptBlockTexteq
set-psbreakpoint
1
process.argsin
--help
1
process.argsin
--version
1
process.argsin
-h
1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Platform (all)
Domain (all)

Sigma 6 rules

Elastic 2 rules

Splunk 3 rules