DiskFiltration begins after malware is already running on an air-gapped machine that contains a mechanical hard-disk drive. Instead of using speakers, the malware deliberately issues disk operations that move the HDD actuator arm in controlled patterns. Those mechanical movements create acoustic emissions at frequencies that can be selected and modulated by…
Inspect the ClaimsCase · DiggingBeagle record
DiskFiltration encoded secrets in hard-drive actuator noise
DiskFiltration research generated controlled acoustic emissions by moving an HDD actuator arm and decoded the signal with nearby consumer devices.
Scope
Laboratory research applicable to mechanical HDDs; it requires compromised code and a nearby receiver and does not apply to solid-state-only systems.
Assessment profile
Assessment method- Setting
- research demonstration
- Exploitation
- demonstrated
- Evidence
- Grade B
Basis and provenance
The cited actuator-frequency and measured-range claims establish a mechanical-HDD laboratory channel; SSD-only systems and initial compromise are outside the demonstrated result. Assessment is a desk review of the retained canonical Claims and cited Source metadata at their recorded cutoff, not a new external verification. Impact remains ungraded.
Assessed Sep 24, 2026 using diggingbeagle.assessment/1.
Evidence basis: CLM-DISKFILTRATION-RATE · CLM-DISKFILTRATION-MECHANISM · DiskFiltration: Data Exfiltration from Speakerless Air-Gapped Computers via Covert Hard Drive Noise
At a glance
The demonstrated impact is low-bandwidth exfiltration of compact secrets from an already-compromised HDD-based system. The broader lesson is that removing speakers does not create an 'audio gap' when other mechanical components remain software-controllable. For modern environments the applicability question is straightforward: SSD-only systems remove this…
Read the implicationsThe cited work does not establish practicality on systems without controllable mechanical HDDs. Range and decoding reliability depend on drive model, chassis acoustics, ambient noise and receiver placement. The experiment demonstrates exfiltration after compromise; it does not establish a method for initially infecting an air-gapped host. No cited evidence…
Limits and uncertaintyFull account
DiskFiltration begins after malware is already running on an air-gapped machine that contains a mechanical hard-disk drive. Instead of using speakers, the malware deliberately issues disk operations that move the HDD actuator arm in controlled patterns. Those mechanical movements create acoustic emissions at frequencies that can be selected and modulated by software.
A nearby microphone-equipped device records the sound and decodes the modulation. The important physical fact is that a hard drive is not only a storage device: its actuator is an electromechanical component whose motion produces sound. If software can control the motion precisely enough, an unintended mechanical side effect becomes a low-bandwidth transmitter. The paper reports 180 bits per minute and distances up to two meters in its tested setups.
The result is bounded. It requires prior compromise, a controllable mechanical HDD, suitable acoustic conditions and a receiver within range. It does not apply to SSD-only systems, and it does not demonstrate remote compromise or bulk network-like throughput.
Mechanism and trust boundary
- 01
Gain code execution on the isolated host
DiskFiltration assumes malware is already present and can generate storage operations; it is not an initial-access technique.
Boundary: air-gapped host / attacker-controlled code
- 02
Translate data into disk-access patterns
The malware encodes secret bits into a sequence of HDD operations chosen to control actuator movement.
Boundary: secret data / storage workload
- 03
Move the actuator arm deliberately
Seek activity drives the mechanical actuator, producing controllable acoustic emissions without speakers or audio hardware.
Boundary: software-controlled I/O / electromechanical motion
- 04
Capture the acoustic signal nearby
A smartphone, smartwatch, laptop or other microphone-equipped receiver records the emitted pattern within the practical range.
Boundary: protected machine / surrounding acoustic environment
- 05
Demodulate the secret
Receiver software identifies the encoded acoustic pattern and reconstructs the transmitted data.
Boundary: microphone recording / recovered data
Claims & evidence
CLM-DISKFILTRATION-RATEThe paper reports an effective rate of 180 bits per minute at distances up to two meters in the tested setup.supported
Basis: reported finding
- supportsDiskFiltration: Data Exfiltration from Speakerless Air-Gapped Computers via Covert Hard Drive Noiserole not specified
Abstract, reported rate and range
CLM-DISKFILTRATION-MECHANISMDiskFiltration demonstrated a speakerless acoustic covert channel by controlling HDD actuator movement to generate specific sound frequencies.supported
Basis: reported finding
- supportsDiskFiltration: Data Exfiltration from Speakerless Air-Gapped Computers via Covert Hard Drive Noiserole not specified
Abstract, mechanism description
Implications
The demonstrated impact is low-bandwidth exfiltration of compact secrets from an already-compromised HDD-based system. The broader lesson is that removing speakers does not create an 'audio gap' when other mechanical components remain software-controllable. For modern environments the applicability question is straightforward: SSD-only systems remove this specific actuator channel, while systems retaining mechanical disks may still inherit the physical prerequisite.
Controls and mitigations
- Prefer SSD-only storage for systems where the threat model justifies eliminating this mechanical actuator channel.
- Keep untrusted microphone-equipped devices outside the protected hardware zone so a practical receiver is not available.
- Use acoustic monitoring only where the environment and risk justify it, focusing on repeatable patterned emissions rather than ordinary disk noise.
- Constrain untrusted code execution and suspicious storage workloads because the channel requires software control of HDD activity.
Unknowns and contradictions
- The cited work does not establish practicality on systems without controllable mechanical HDDs.
- Range and decoding reliability depend on drive model, chassis acoustics, ambient noise and receiver placement.
- The experiment demonstrates exfiltration after compromise; it does not establish a method for initially infecting an air-gapped host.
- No cited evidence shows an AI system autonomously selecting or operating this channel in deployment.
Sources and citation
Material revision history
- Sep 19, 2026 · Published version · first publication · revision 15
- Sep 19, 2026 · Published version · material revision · revision 20Public fields changed: attack_path, implications, mitigations, narrative, unknowns
- Sep 25, 2026 · Published version · material revision · revision 36Public fields changed: assessment_profile