---
id: "phishing-018"
title: "Fake Colleagues on Video Calls: How to Spot a Live Deepfake"
description: "Learn how to detect deepfakes during business video calls. Spot visual flaws, audio anomalies and real-time defences against live AI impersonation."
canonical: https://startbrain.io/en-gb/cybersecurity/spot-live-deepfake-video-calls/
slug: "spot-live-deepfake-video-calls"
date: "2026-09-25"
category: "phishing"
product: "deepfakestudio"
lang: en-gb
author: "Brain Security · Cyber & Human Risk R&D"
frameworks: "NCSC · Cyber Essentials · UK GDPR · NIS 2 · ISO 27001"
---

# Fake Colleagues on Video Calls: How to Spot a Live Deepfake During a Meeting

The scenario felt like science fiction until recently, but it is now hitting organisations with full force. A chief financial officer or an operations director dials into a Microsoft Teams, Zoom or Google Meet call. Their face looks familiar, their tone of voice sounds identical, and the business context appears completely plausible. Yet the individual on the screen does not exist: it is a synthetic video stream generated in real time by attackers aiming to divert funds or compromise high-privilege credentials.

For CISOs and executive boards, this new breed of CEO fraud rewrites the risk landscape. Visual trust collapses against generative AI engines capable of cloning a colleague using merely minutes of publicly available footage. So, how can organisations effectively detect a deepfake in business video calls without stalling day-to-day operations?

---

## What are the visual and vocal signs of a deepfake in a video meeting?

> **In summary: To detect a live deepfake, watch for lip-sync latency, unnatural eye blinking, warping around facial edges during fast movements and metallic audio anomalies, all of which stem from the computational strain of real-time cloning algorithms.**

Visual generative AI has made incredible strides, yet real-time rendering demands immense computational throughput that inevitably produces technical artifacts. By scrutinising suspicious video feeds, security leaders and staff can identify distinct warning signs:

- **Lip-sync latency and micro-pauses:** Mouth movements fail to line up seamlessly with the spoken syllables. A slight delay of a fraction of a second often persists between the audio wave and the mouth kinetics.
- **Distorted facial borders and mismatched lighting:** When an impersonator turns their head or brings a hand across their cheek, the visual mask flickers, blurs or stretches around the jawline. Furthermore, the light source illuminating the face rarely matches the ambient lighting of the background.
- **Rigid expressions and robotic blinking:** Generative models still struggle to emulate organic blinking patterns or micro-saccadic eye movements. The individual often appears to stare into the webcam with an unnatural, fixed intensity.
- **Metallic audio artifacts:** Real-time synthetic voice cloning often yields flat cadence, a lack of spontaneous emotional inflection and subtle digital background noise during transitions between sentences.

---

## How can you test an impersonator during a live call using behavioural checks?

> **In summary: Trap an impersonator by requesting sudden profile head turns, asking them to pass a hand directly across their face, or raising unexpected internal context questions that no external threat actor can answer on the spot.**

When an unusual request or uncharacteristic behaviour raises suspicions, do not wait until the call concludes to react. Attackers rely on controlling the agenda by citing a poor connection or manufactured corporate emergencies. Several immediate techniques can break the algorithmic illusion:

### 1. Enforce physical disruptions to the video feed
Ask the participant to turn their head 90 degrees to show their profile, or wave a hand right in front of their nose. Most real-time facial reenactment tools lose track of key facial landmarks such as the eyes and mouth, causing the digital overlay to glitch, tear or disappear altogether.

### 2. Introduce unscripted context questions
Cybercriminals prepare their social engineering scenarios meticulously, yet they remain blind to everyday office culture. Ask an unexpected question that falls completely outside the script: *"By the way, did they finally fix the coffee machine on the third floor?"* or *"Can you recall the name of the new intern who joined our team catch-up yesterday?"*. Hesitation or evasive answers strongly point towards deception.

---

## Why is practical experimentation the only durable defence?

To equip employees against such sophisticated impersonation, standard slide decks and static policies are no longer enough. Staff members must interact with the technology first-hand to grasp its vulnerabilities and build reliable defensive reflexes.

This experiential philosophy underpins the tools built by Brain Security, including [Deepfake Studio](/en-gb/catalog/deepfake-studio/), our educational deepfake creation sandbox accessible online free of charge without creating an account. By generating their own synthetic video and voice clones in a safe environment, staff directly observe the ease of creation alongside the recurrent visual flaws. This hands-on engagement demystifies generative threats far more effectively than passive security briefings.

Moreover, these practical learning workshops provide tangible measures to support AI risk culture and awareness, directly aligning with internal governance goals and the proactive measures expected under Article 4 of the EU AI Act.

---

## Which operational safeguards counter urgent financial requests?

Even with well-trained employees, advanced social engineering can occasionally slip past human attention. Enterprise security must therefore rest on a non-negotiable operational principle: never authorise critical actions based solely on a video call.

- **Out-of-band verification:** Any request involving urgent bank transfers, modified payment details or the sharing of administrative credentials must require dual validation via an independent, pre-approved channel (such as a direct phone call using an established internal directory or a verified corporate message).
- **A clear call-drop protocol:** Embed a straightforward rule across the organisation: if in doubt, hanging up immediately and calling back on a known, verified extension is never treated as a breach of professional etiquette.

To test your workforce against real-time interactive threats and explore how to weave practical awareness tools into your security culture, [book a demo](/en-gb/book-a-demo/) to discuss your requirements with our team.

### Risk & Countermeasure Matrix: Fake Colleagues on Video Calls: How to Spot a Live Deepfake

| Critical Point Identified | Operational Analysis & Mechanism | Guide Section |
| --- | --- | --- |
| **Lip-sync latency and micro-pauses** | Mouth movements fail to line up seamlessly with the spoken syllables. A slight delay of a fraction of a second often persists between the audio wave… | What are the visual and vocal signs of a deepfake in a video… |
| **Out-of-band verification** | Any request involving urgent bank transfers, modified payment details or the sharing of administrative credentials must require dual validation via… | Which operational safeguards counter urgent financial requests? |
| **Distorted facial borders and mismatched lighting** | When an impersonator turns their head or brings a hand across their cheek, the visual mask flickers, blurs or stretches around the jawline… | What are the visual and vocal signs of a deepfake in a video… |
| **A clear call-drop protocol** | Embed a straightforward rule across the organisation: if in doubt, hanging up immediately and calling back on a known, verified extension is never… | Which operational safeguards counter urgent financial requests? |

---

## Further reading: related articles and Brain Security solutions

### Related articles on this topic

- **[Why HR Departments Are Prime Targets for Phishing (and How to Respond)](/en-gb/cybersecurity/why-hr-departments-are-phishing-targets/)** (Phishing & Social Engineering) : Discover how to protect recruitment teams from human resources phishing and malicious CVs with tailored, realistic training simulations.
- **[Internal Phishing: What to Do When Malicious Emails Come from a Colleague](/en-gb/cybersecurity/internal-phishing-compromised-colleague-email-response/)** (Phishing & Social Engineering) : Has a suspicious email arrived from a genuine colleague's account? Learn how to spot internal phishing and contain compromised corporate inboxes.
- **[Infostealers: Why Saving Corporate Passwords in Unmanaged Browsers Puts Organisations at Risk](/en-gb/cybersecurity/infostealers-password-theft-unmanaged-browsers/)** (Phishing & Social Engineering) : Learn how infostealers harvest corporate credentials and session cookies from unmanaged web browsers to bypass MFA and breach enterprise networks.
- **[Finance Teams: 5 Scam Scenarios to Test Across Your Treasury Department](/en-gb/cybersecurity/finance-treasury-scam-scenarios-simulation-training/)** (Sectors & Roles) : Fake mandates, invoice fraud and audio deepfakes: discover the targeted social engineering attacks threatening finance teams and how to train staff.

### Explore Brain Security solutions on our website

- **Featured solution : [Deepfake Studio](/en-gb/catalog/deepfake-studio/)** : The deepfake photobooth: allow your webcam, watch an AI transform you live, and never look at an image the same way again.
- **[Browse use cases by security goal and sector](/en-gb/use-cases/)**
- **[Compare our cybersecurity and AI awareness formats](/en-gb/compare/)**
- **[Explore the full interactive Brain Security catalogue](/en-gb/catalog/)**
- **[Discuss your needs with our team (demo and setup)](/en-gb/book-a-demo/)**

---

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