New Enterprise Attack Vector
SOURCE: Trescudo Intelligence • Author: Evangeline Smith, MarCom • September 19, 2025)
The Insecure Echo: How Voice Assistants Became the New Enterprise Attack Vector
"Hey Siri, what's the weather?"
"Alexa, play my morning playlist."
"Bixby, call the office."
Voice assistants have seamlessly woven themselves into the fabric of our daily lives. They are the epitome of convenience, the ever-present digital butlers in our homes, cars, and pockets. But this convenience has a hidden cost. For every organization, these "always-on" listeners have quietly opened a new, deeply personal, and often unmonitored, attack vector directly into the enterprise.
The truth is, your security perimeter is no longer just your network or your cloud; it's the ambient sound in your CEO's home office. Understanding and managing this new "acoustic attack surface" is one of the next great challenges for modern cybersecurity.
The Core Vulnerabilities: How the Echo Becomes a Threat
The risks posed by voice assistants are not theoretical. They stem from the very design that makes them so useful, creating three primary areas of vulnerability:
Passive Eavesdropping: By design, these devices are constantly listening for a wake word. While they are not supposed to transmit data before being activated, research and real-world incidents have repeatedly shown that accidental activations and the recording of conversational "snippets" are common. This data, stored and analysed in the cloud, becomes a high-value target for corporate espionage.
Malicious "Skills" and Third-Party Risk: The functionality of voice assistants is extended by an ecosystem of third-party apps or "skills." These are often developed with far less security oversight than the core platform. Attackers can create malicious skills designed to eavesdrop on users, create fake password prompts, or deliver sophisticated phishing attacks through the voice interface.
Inaudible Commands: Perhaps the most insidious threat is the use of ultrasonic, inaudible commands to control devices. This technique, which is undetectable by the human ear, can be used to issue secret commands to any nearby voice assistant.
Case Study: The "Dolphin Attack"
The "Dolphin Attack" is not science fiction; it is a proven, real-world attack vector demonstrated by researchers at Zhejiang University.
The How: Researchers successfully embedded high-frequency, ultrasonic commands—inaudible to humans—into everything from YouTube videos to public address systems. These secret commands were picked up and flawlessly executed by the microphones in popular voice assistants.
The Impact: In their demonstration, the researchers were able to make a target's phone secretly initiate a video call, open a malicious website, and even manipulate the navigation system of a car. The potential for harm is enormous: an attacker could embed a command in a seemingly benign video to tell your phone to "transfer money" or "unlock the front door."
This case study proves that an attacker doesn't need to be in the room to control your most personal devices. They just need to be within "earshot" of the microphone.
Quote from Derick Smith, CEO, Trescudo:
"The 'Dolphin Attack' is a perfect example of how the threat landscape evolves. Attackers are brilliant at turning a feature into a bug. The convenience of an always-on microphone becomes a critical vulnerability, and it proves that our security strategy must extend beyond the screen to the very air around us."
The CISO's Playbook: Countering the Voice Threat
For CISOs, the proliferation of voice assistants means the "human perimeter" has expanded. An attack on an employee's personal device can be a direct bridge into your corporate network. A proactive defence is essential.
Here is a playbook for mitigating this emerging risk:
Establish a Clear Governance Policy:
Define where and how voice-activated devices can be used, especially in sensitive areas like boardrooms, R&D labs, and executive offices.
Create clear guidelines for employees on securely configuring their personal devices, such as disabling voice-activated purchasing or enabling PIN protection for sensitive actions.
Update Your Social Engineering Training:
Your employees are trained to spot a phishing email. They need to be trained to spot a "vishing" (voice phishing) attack delivered by a malicious skill.
Run Drills: Incorporate voice-based scenarios into your regular security awareness training. A simple drill could involve a simulated prompt from a malicious skill asking a user to "verbally confirm your network password for a security update."
Educate on Inaudible Threats: Make employees aware that their devices can be activated silently. Advise them to be cautious about the media they play near their devices and to review their voice assistant's activity history regularly.
Reinforce Your Technical Defenses:
The goal of many voice-based attacks is to bypass or steal credentials. A robust Identity & Fraud Prevention strategy, built on the principles of Zero Trust, is your most effective technical defense.
Treat the ecosystem of third-party "skills" as part of your supply chain. A modern Vulnerability Management program should include policies for assessing the risk of third-party applications that have access to corporate or personal devices.
Quote from Marçal Santos, (CISM, CDPSE), Trescudo:
"Ultimately, you cannot control every device an employee uses. Therefore, you must control what those devices can access. A Zero Trust approach that rigorously authenticates every single request, regardless of its origin, is the only way to neutralise the threat of a compromised voice assistant."
From Theory to Action
Voice assistants are not a passing trend; they are a permanent feature of our technological landscape. To ignore them is to ignore one of the fastest-growing attack vectors into your organisation.
By combining clear governance, targeted employee training, and a robust, Zero Trust security architecture, you can safely embrace the convenience of voice technology without falling victim to its hidden risks.
Is your security posture prepared for a threat that doesn't need to be seen to be heard? Schedule your complimentary Cyber Resilience Strategy Session to assess your human perimeter and build your roadmap to resilience.
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Verified Intelligence Sources & Further Reading
Inaudible Voice Commands / Dolphin Attack:
Malicious Alexa Skills:
Voice Assistant Privacy: