Full Report
A new open-source tool named 'Chirp' transmits data, such as text messages, between computers (and smartphones) through different audio tones. [...]
Analysis Summary
# Tool/Technique: Chirp (Data-over-Audio Tool)
## Overview
Chirp is an open-source tool that utilizes audio tones, transmitted via a speaker-microphone configuration, to transfer data between devices. It is described as a "fun new approach" to a known concept, allowing near-device communication without relying on traditional wireless technologies.
## Technical Details
- Type: Tool
- Platform: General (Implied to work on any device capable of playing and recording sound, such as computers and smartphones)
- Capabilities: Transmitting and receiving short data messages using sound waves. Based on the `ggwave` library.
- First Seen: Context suggests development/disclosure around the time of the article, leveraging the `ggwave` library developed by Georgi Gerganov.
## MITRE ATT&CK Mapping
*(Note: As this is primarily a practical data transfer tool, direct, specific offensive TTP mappings are weak without operational context. The technique primarily relates to data staging or exfiltration when misused.)*
- T1567 - Exfiltration Over Alternative Protocol (If used to exfiltrate data)
- T1567.002 - Exfiltration Over Physical Medium (A stretch, but data is transferred via acoustic wave/physical medium)
## Functionality
### Core Capabilities
- Data transmission and reception using modulated audio signals (sound waves).
- Operates in an open-source manner, with the online application running entirely client-side and functioning offline.
- Leverages the `ggwave` library for sound signal generation and processing.
### Advanced Features
- The developer plans to experiment with using **hypersonic sounds** to make message exchanges inaudible (stealthier).
- **Limitation:** Stops listening for messages while actively transmitting, meaning simultaneous received data may be lost.
- **Limitation:** Currently lacks error correction or redundancy, making it susceptible to high error rates in noisy environments or with low speaker volume.
## Indicators of Compromise
- File Hashes: [Not provided in context]
- File Names: [Not provided in context]
- Registry Keys: [Not applicable/provided]
- Network Indicators: [None observed; the online application operates client-side/offline, and the tool itself is generally not network-dependent for core function.]
- Behavioral Indicators: Generation of audible (or potentially hypersonic) sound signals for data transfer; utilization of speaker and microphone simultaneously in an unusual data transfer pattern.
## Associated Threat Actors
- Initial use context involves researchers and developers experimenting with LLMs and data-over-sound proof-of-concepts (e.g., solst/ICE, Georgi Gerganov).
- **Related Concept:** This technique is related to the data exfiltration attack dubbed 'MOSQUITO' (developed in 2018).
## Detection Methods
- Signature-based detection: Analyzing binaries utilizing the `ggwave` library or specific audio modulation patterns.
- Behavioral detection: Monitoring for sustained, bidirectional speaker/microphone use during an active data transfer session that correlates with unusual file processing.
- YARA rules: [Not available]
## Mitigation Strategies
- Limit applications' access to microphone hardware if not strictly necessary for the device's function.
- Implement acoustic monitoring solutions capable of detecting ultrasonic or unusual high-frequency audio signaling if the environment dictates heightened security (e.g., high-security facilities).
- Noise cancellation software on microphones might interfere with or distort data transfer.
## Related Tools/Techniques
- MOSQUITO (Data exfiltration technique using speakers/headphones, dating from 2018).
- ggwave (The underlying compact data-over-sound library utilized by Chirp).
- Chirp.io (The commercial product owned by Sonos, which served as inspiration).