Service Design

Detecting and Preventing Voice Phishing Scams

Project Overview

Phishing Hunter aims to prevent scam damage before it happens and minimize recovery effort and cost after incidents. By providing real-time AI alerts, it helps users recognize threats early and take immediate action.

Project type
Team Project (80%)
Duration
8 Weeks
Role
Research, UX/UI Design, Prototyping, Usability Test
Tools
Figma, FigJam

Background

Why Does Voice Phishing Keep Increasing — And Why Won’t It Stop?

Is This Just a Technical Problem — or Something More Deeply Rooted?

That was the very first question that sparked this project. Despite years of public awareness campaigns, voice phishing in Korea continues to increase, causing serious financial loss and emotional trauma for countless victims. That’s why I approached this project as a way to create meaningful design solutions.

Trends in Voice Phishing Incidents and Damages
Trends in Voice Phishing Incidents and Damages

Main Features

Incoming Call Risk Alert

AI Warns You Before You Answer

AI analyzes incoming calls and highlights potential scam risks before the call is answered. By showing clear visual warnings at the right moment, it helps users pause and make safer decisions.

Report in Main Home

One-Stop Report: Turning Scam Awareness into Immediate Action

Easily report suspicious calls in one tap right after AI detection. It guides you through the reporting process. No more confusion or delays - everything you need is handled in one place.

Tracking Alerts After Incident Report

Follow Your Report Until It’s Resolved

Users can easily track their report status after submission. Clear updates and notifications provide reassurance, letting users know they are still being protected until the case is resolved.

Empathize

When Are Users Most Vulnerable to Scams?

Desk Research

Breaking Down the 4 Stages of a Scam

We conducted desk research using 10 news reports, 10 academic studies, and conversations from online scam communities, and analyzed the data, which showed that digital scams occur in 4 stages.

Academic Research Findings
Academic Research Findings

Insights from Desk Research

This four-stage structure became a key framework for clearly understanding why users fail to recognize risk at each stage and where they are most vulnerable.

  1. Pre-incident

    • Lack of user preparedness
    • Insufficient information
    • Low awareness of risks
  2. During Incident

    • Loss of judgement due to urgency and fear
  3. Post-incident

    • Delayed recognition
    • Late awareness
  4. Recovery

    • Difficulty of recovery

1:1 Depth Interview

The Most Critical Moments Are Before and During the Scam

We conducted semi-structured interviews with 5 participants to understand the pain points users experience across the 4 stages of digital scams. Through this, we discovered that users feel the most confusion and pressure before and during the scam.

Interview with Participant A
Interview with Participant A
Interview Protocol
Interview Protocol
Interview Responses
Interview Responses
Mapping Interview Insights
Affinity Mapping
Affinity Mapping

Define the Problem

To Prevent Harm, Act Before or During the Scam

Most pain points arise before and during the incident. However, the recovery is complex and stressful. Therefore, the solution should focus on stopping the scam before it happens.

Key Stage to Step In
Key Stage to Step In

Define: Problem Statement

Users Want to Prevent Scams, But Most Solutions Act Too Late.

Persona and User Journey Map

Two Personas Reveal Where Users Are Most at Risk

Using the interview insights, we developed two personas and journey maps to clearly identify users’ key problems and pain points.

One persona represents a man in his 50s who is vulnerable to scams due to lower digital literacy, financial stability, and strong family responsibilities.

Lee’s Persona
Lee’s Persona
Lee’s Journey Map
Lee’s Journey Map

The other persona represents a young woman with no work experience or financial literacy, making her highly susceptible to financial fraud.

Park’s Persona
Park’s Persona
Park’s Journey Map
Park’s Journey Map

Ideate

How Might We Intervene Early in the Pre-Incident Stage?

Ideation (Brainstorming)

18 AI Ideas to Warn, and Pause Risky Actions Early

We analyzed 14 user behavior and risk-related data points. Through broad ideation, we generated 18 AI-driven intervention ideas. From these, we narrowed down MVP focused on early risk detection, emotional calming, and pausing risky actions before damage occurs.

AI-Driven MVP Feature Brainstorming
AI-Driven MVP Feature Brainstorming

MoSCoW Prioritization

Focusing on What Truly Prevents Damage

We prioritized features using the MoSCoW method to focus on the most essential functions—those that help detect phishing early, alert users, and minimize potential damage.

MoSCoW
MoSCoW

Storyboard

What Changes When Early Warning Exists?

This storyboard demonstrates how AI automatic detection intervenes before users fall for a scam - warning them in real time and stopping harmful actions early.

Storyboard

User Flow

Don’t Make Users Work. AI Works Everything.

This user flow shows how AI reduces user effort by automatically detecting scams, delivering timely warnings, and guiding users through safe actions.

User Flow
User Flow

Sketches

Sketching Fast to Explore Safer Interactions

I quickly sketched to explore layout and interaction ideas before prototyping.

Sketching
Crazy 8s
Crazy 8s

Low-Fidelity Wireframe

Visualizing Key Flows Before High-Fidelity Design

We designed low-fidelity wireframes to explore key layout options based on my sketches. Before moving to high-fidelity prototypes, we focused on visualizing ideas such as user flow quickly, rather than refining visual details.

Prototype

Can Users Recognize the Warning Signs?

Design System

Establishing Consistency and Efficiency

I built a design system to ensure visual consistency, scalability, and efficient prototyping across the app.

01. Typography

02. Characters

03. Colors

04. Components

05. Warning Signs

06. Light/Dark Mode

Final Designs

Detecting and Preventing Voice Phishing Scams

Incoming Call Risk Alert

Alerting

AI Detects Different Warning Signs Based on Report History

The AI provides different warning signs based on the number of scam reports associated with the caller. When the risk is high, the system automatically ends the call and seamlessly guides users into the reporting flow.

Report in Main Home Screen

One-Stop Report

Fast and Simple Reporting

Post-incident, users can quickly report a scam from the home screen by filling in the report details. Once the report is completed, they can access More on anti-phishing services to check My Report Status and follow next steps.

Check Progress

Tracking

Stay Informed, Stay Reassured

After submitting a report, users receive real-time updates on its progress. Clear notifications help users understand which stage their case is in, providing reassurance and transparency even after the report is completed.

View Notification

Notification

Immediate Updates, No Guesswork

Phishing Hunter sends clear, real-time notifications when action is needed. Even after an incident, users stay informed and reassured through proactive alerts.

Usability Test

Evaluating and Improving Experience

We conducted a usability test with 8 participants across 4 tasks to observe how users interacted with the product in real scenarios.

Usability Test with Participant A
Usability Test with Participant A
Usability Test with Participant B
Usability Test with Participant B

With an average SUS score of 86.3, Phishing Hunter achieved an excellent usability rating. However, a few specific things received relatively lower scores. We looked deeper into these responses to understand why users felt uncertain in those areas.

SUS Score
SUS Score
Data Analysis
Data Analysis

Takeaways

What I Focused On

01Understanding Hidden Pain Points

Users often explain what feels difficult, but the real problems are not always clearly stated. By looking beyond words and focusing on user behavior and data, I learned how to uncover deeper pain points that users may not be aware of themselves.

02Understanding the Role of Technology

I realized how technologies like AI, ML, DL and NLP help detect scam patterns that people often miss. Instead of focusing only on screens and UI, I began to think about scam prevention as a system that can spot risks early and step in at the right moment to protect users.

03Designing Within Technical and Policy Constraints

Working on a finance-related domain helped me understand how much design is affected by technical limits and rules. I learned that good UX design is not only about how things look, but about making thoughtful decisions that also consider technology, security, and policies.

Other projects

← All work