Fraud Detection Machine LearningA “Smart” Move for Merchants

David Pirtle | July 7, 2025 | 15 min read

This featured video was created using artificial intelligence. The article, however, was written and edited by actual payment experts.

What is Fraud Detection Machine Learning Technology?

In a Nutshell

Thinking of new ways to fight fraud? Technology may hold the answer. In this post, we’ll discuss what fraud detection machine learning technology is and how it works. We’ll also outline the benefits and show you some areas where it may — or may not — help you stop criminals.

Will Machine Learning be Your Secret Weapon Against Both First- & Third-Party Fraud?

It’s no secret that digital fraud is getting worse by the year. Recent data released by LexisNexis Risk Solutions found that North American eCommerce merchants spent $4.61 to investigate and resolve every dollar lost to fraud; the highest on record.

Chief among the culprits behind the rise in online fraud is the rapid proliferation of generative artificial intelligence. Text-to-image tools and chatbots are enabling anyone with an internet connection to spin up difficult-to-spot deepfakes and convincing spam texts. These dual threats are making scams like new account fraud and account takeover increasingly common.

The statistics speak for themselves: deepfake attacks exploded by fourfold between 2020 and 2024, and today make up 7% of all fraud attacks.

So, what can merchants do to counter the rise in AI-enabled fraud? Well, fighting fire with fire by implementing an AI and machine learning-based approach to fraud detection could be the answer.

Common QuestionWhat is machine learning?Machine learning is often described as artificial intelligence. This is because it appears to give computers the ability to learn the same way that humans learn. In reality, instead of trying to mimic human thinking, machine learning simply compares facts and draws the most logical conclusions. The computer is not literally “thinking” in the same way as a human. However, every new bit of information helps refine the algorithm. This makes the computer “smarter” in a real sense.

What is Fraud Detection With Machine Learning?

Machine learning means a computer uses experience and data to automatically improve its own capabilities. The program tests incoming information to see if it either contradicts or reinforces an existing algorithm, then adjusts accordingly. The more data the machine receives, the more reliable its predictions will be.

The machine learning model of fraud detection is a technology-powered strategy that compares incoming information against historical data prior to approving a transaction. The machine learning model uses sophisticated algorithms to analyze results, effectively “learning” from each new input.

Conventional (“Rules-Based”) Fraud Detection vs. Machine Learning

Rule-Based Fraud Detection
Detects obvious fraud incidents
Requires manual oversight to develop rules
Multiple verification steps introduce friction
Long-term processing
VS
ML Fraud Detection
Finds hidden correlations in data
Develops rules based on observed data trends
Minimizes customer-facing “negative” friction
Real-time processing

Machine learning fraud detection models can be trained using examples of good and bad transactions. And, with more training, it’s able to identify fraud activity in real-time with more information. Thus, the system gets better and more accurate over time.

The model calculates a score that reflects the transaction’s fraud risk based on everything it learns. The final score is compiled from multiple elements, with different factors weighted more heavily than others, and is used to make a decision: accept the transaction, reject it, or flag it for manual review by a human.

The entire decisioning process typically takes less than a second. The customer is totally unaware that it even happened. The information extracted from the transaction is then fed back into the model, further refining the algorithm.

The entire decisioning process typically takes less than a second. The customer is totally unaware that it even happened. The information extracted from the transaction is then fed back into the model, further refining the algorithm.

Advantages of Using Machine Learning to Detect Credit Card Fraud

As we established, machine learning fraud detection technology works by comparing new information against what it already knows. Humans go about the decision-making process in the same way, so why rely on a machine?

Well, ML technology offers a few key advantages:

  • It’s Faster: Robust machine learning algorithms can analyze complex transaction data and render a risk score in a split second.
  • It’s More Accurate: ML models analyze much more information than a human can. They’re able to detect even subtle fraud patterns, free of human bias or error.
  • It Gets Better: With good input, machine learning models will improve with each transaction. A machine learning fraud detection system grows with your business.
  • It’s Proactive: ML models learn from bad actors and normal behavior. The algorithm can proactively identify fraud before a bad transaction gets processed.
  • It Saves Money: A computer can run more comprehensive data checks than a room full of human analysts. It lets you reallocate staff where they’re most needed.
  • It’s Adaptive: Legacy systems depend on preset, static responses. A fraud detection model, however, is designed to adapt to new information on its own.

Done correctly, fraud detection machine learning is a highly effective way to identify and prevent fraud. That doesn’t mean it’s perfect, though.

How Does Fraud Detection With Machine Learning Work?

TL;DR

Fraud detection machine learning can be thought of as a five-step process involving data ingestion, feature extraction, prediction, and a final output. The entire process takes less than a second to complete.

Machine learning fraud models make fraud decisions in real-time. The process of data ingestion, analysis, and output all occur at the blink of an eye. In total, the workflow takes less than one second to complete.

Here is how it works in practice:

Step #1  |  Data Ingestion

First, the fraud detection system takes in thousands of available data points associated with a transaction. Everything from IP addresses, email addresses and billing details to device fingerprints, geolocation data, and behavioral information (like touchscreen gestures or typing speeds) are taken into account.

Step #2  |  Feature Extraction

Next, the system prepares the raw data for analysis. Through a process called feature extraction, the model processes, transforms, and aggregates the datapoints into a format that can be understood by the machine learning model. For example, the system may examine the domain associated with an email address by recording features like the domain’s age, risk level, and data breach history.

Step #3  |  Prediction

Now, the core analysis occurs. The extracted features are run through the trained algorithm which assesses and weighs each feature simultaneously. Depending on the model’s training data, a new account using a proxy server might carry a heavy weight, while an address verification service (AVS) mismatch might carry a lighter weight. The system processes all these factors and reduces them down to a simplified fraud risk score, typically on a scale of 0 to 100.

Step #4  |  Rule Application

Your pre-set fraud logic and risk thresholds are layered on. For instance, you may have a preexisting rule that flags all transactions over $2,000 for manual review, regardless of risk score. To reduce buyer friction, you may have another rule that automatically accepts transactions from a trusted customer, regardless of red flags present.

Step #5  |  Output & Delivery

Based on the fraud score from Step 3 and your custom rules in Step 4, the system outputs one of three decisions: accept the transaction, decline it, or flag it for review by a live human. This final decision is then relayed to your payment gateway or eCommerce platform so that they may complete the transaction in question.

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What Data Points are Used?

TL;DR

Machine learning-based fraud detection analyzes data points including transaction details, behavioral indicators, device and network information, and the buyer’s transaction history.

A machine learning-based fraud detection system is powerful because it is able to analyze a vast array of data from every transaction in real time. These data points include:

Transaction & Order Details

Payment data surrounding the customer’s card type, transaction amount, and currency make up core components of the transaction.

Here, contextual details like geolocation data or the time elapsed between add-to-cart actions and checkout can provide clues as to whether the transaction fits established patterns.

  • Card Type
  • Payment Method
  • Transaction Amount
  • Currency
  • Product SKUs
  • Product Quantities
  • Shipping Costs
  • Transaction Timestamp
  • Time Between Carting & Checkout
  • Session Duration
  • Billing/Shipping Addresses
  • IP Geolocation
  • Time Zone

Behavioral Indicators

Beyond the transaction details, the system analyzes how the customer interacts with your site. This is important because fraudsters and legitimate buyers often behave in very different ways.

For example, a real customer may browse multiple product pages and read reviews, before gradually adding items one by one to their cart over several minutes. A fraudster, on the other hand, may navigate directly to a high-value item, add several to their cart at once, and immediately proceed to checkout.

  • Browsing Time
  • Pages Visited
  • Cart Abandonment
  • Typing Speed
  • Copy/Paste Usage
  • Form Completion Patterns
  • Cursor Movements
  • Click Patterns
  • Page Flow
  • Login Frequency
  • Password Change Attempts
  • Contact Info Updates

Device Fingerprint

Every device and connection has a unique digital identity that can be used to spot risk. For example, data about a device’s operating system, browser type, language settings, and installed fonts can be used to compile a unique “fingerprint” that can be tracked over time, even if the customer attempts to hide their tracks.

  • Screen Resolution
  • Browser Type
  • Device Operating System
  • Installed Fonts
  • Plugins
  • Language Settings
  • IP Address
  • Connection Type
  • Proxy Usage
  • Device ID
  • Browser Fingerprint
  • Canvas Fingerprinting

Network Analysis

Network details, like the use of a VPN connection, proxy service, or anonymous browser, can be used to flag anomalies. While this is more removed than specific device data, network information can still offer key insights about a customer’s intentions.

  • Known Networks Associated With Fraud
  • Residential vs. Datacenter IPs
  • Tor Usage
  • Anonymization Services
  • IP Location vs. Billing Address
  • Multiple Accounts From Same IP
  • Unusual Geographic Velocity

Past Transaction Data

Arguably the most powerful feature about a machine learning model is its ability to learn. Your fraud detection system constantly analyzes new and past data to refine its understanding of your fraud environment so that it is able to discern between normal and fraudulent behavior with ever-increasing accuracy.

Your machine learning model learns from approved and declined transactions, delayed feedback (e.g. it takes into account whether a transaction later results in a chargeback). And data from manual transaction review.

  • Transaction Approval/Decline Results
  • Chargeback Notifications
  • Confirmed Fraud Cases
  • Fraud Analyst Reviews & Corrections
  • Periodic Updates Based on New Data Patterns

Common Machine Learning Models for Fraud Detection

We've explored general fraud situations. Now let's dive into building machine learning applications and investigate typical and advanced methods for crafting fraud detection engines.

Anomaly Detection

Anomaly detection, a prevalent anti-fraud approach in data science, categorizes data objects into two groups: normal distribution and outliers. Outliers transactions are those that deviate from the norm and may be fraudulent.

  • Are clients using services as expected?
  • Are user actions and transactions typical?
  • Are there inconsistencies in user-provided information?

This approach provides simple binary answers, useful for situations like requesting additional verification for suspicious transactions. While it may not expose fraud, it supports existing rule-based systems.

Supervised Learning

Supervised learning trains algorithms using labeled historical data. The goal is to predict target variables in future data.

Supervised learning models help create and improve business applications, including:

  • Image and Object Recognition: Identifying and classifying objects from videos or images
  • Predictive Analytics: Building systems that offer insights into business data points, enabling informed decision-making
  • Customer Sentiment Analysis: Extracting and classifying information from large data volumes for understanding customer interactions
  • Spam Detection: Using algorithms to manage spam and non-spam communications effectively

Unsupervised Learning

Unsupervised learning models process unlabeled data, classify it into subsets and detect hidden relationships between data item variables. This process includes:

  • 1. Clustering: Grouping unlabeled data based on similarities or differences
  • 2. Association Rulesets: Discovering correlations between dataset variables
  • 3. Dimensionality Reduction: Reducing data inputs while maintaining dataset integrity

Unsupervised learning allows for rapid pattern detection in large data volumes. Common real-world applications of unsupervised learning are:

  • Computer Vision: Performing visual perception tasks, such as object recognition
  • Medical Imaging: Facilitating quick and accurate patient diagnosis in radiology and pathology
  • Customer Personas: Creating accurate buyer persona profiles to tailor product messaging
  • Recommendation Engines: Developing efficient cross-selling strategies based on past purchase behavior data

Advanced systems can detect anomalies and recognize patterns that signify specific fraud scenarios. Anomaly detection, supervised learning, and unsupervised learning are widely used in anti-fraud systems, either individually or combined, to create more sophisticated anomaly detection algorithms.

Whitebox Machine Learning Systems

TL;DR

Whitebox machine learning models are transparent and interpretable, but potentially less accurate when compared to blackbox models.

When evaluating machine learning models for fraud detection, you may come across the terms “whitebox” and “blackbox.” Your choice of one or the other will have significant implications for performance, control, and transparency.

A whitebox model prioritizes transparency and interpretability. These systems are built on more straightforward, interpretable algorithms like decision trees or logistic regression, allowing you to debug and fine-tune the model with greater ease.

Whitebox Model Pros

Whitebox Model Pros

The main benefit is visibility and clarity. Your fraud team can see exactly which factors and rules led to a transaction being flagged, adjust rules, test new logic, and explain decisions to customers or regulators on a granular level. This comes in handy for complying with regulations like the GDPR.

Whitebox Model Cons

Whitebox Model Cons

The trade-off here is potentially lower accuracy and complexity. Because whitebox machine learning models operate on simpler, human-readable logic, they may lack the ability to detect complex fraud schemes as effectively as a blackbox system.

Blackbox Machine Learning Systems

TL;DR

Blackbox models are opaque when stacked against whitebox systems. But, they can be more accurate and more powerful.

A blackbox model, on the other hand, is designed for maximum predictive power. These systems often use highly complex algorithms, like neural networks, that analyze thousands of data points to find intricate and non-linear connections.

Blackbox Model Pros

Blackbox Model Pros

Arguably the biggest upside to blackbox machine learning models is that they’re more accurate than their whitebox counterparts. This allows them to identify subtle, emerging fraud patterns that simpler models might miss, and makes them exceptionally effective against sophisticated attacks.

Blackbox Model Cons

Blackbox Model Cons

Superior predictive power comes at the cost of transparency. It’s virtually impossible to know how or why a blackbox model comes to a certain conclusion, making it difficult to tweak. For instance, if a buyer’s purchase is declined, you may be left without a clear explanation, which can in turn lead to frustration and damaged trust.

Industry Uses for Machine Learning in Fraud Detection

Machine learning models are already known for their ability to help businesses break down data and create specific, measurable, attainable, realistic, and timely (or “SMART”) goals and action plans. AI-driven fraud prevention transcends industries, requiring only data to function effectively. 

Machine learning fraud detection implementation can already be seen in a number of sectors, including:

Fraud Detection Machine Learning

Securing Digital Wallets & Combating ATO Attacks

As Buy Now Pay Later (BNPL) accounts evolve into online digital wallets, the risk of account takeover (ATO) attacks increases. Fraudsters can exploit compromised accounts to make illegal purchases. The key to safeguarding these accounts lies in understanding user login patterns, which can vary significantly based on factors like market and seasonality. Using machine learning to analyze login data can improve user authentication and enhance account security.

Fraud Detection Machine Learning

Compliance & Fraud Detection for Financial Institutions

Fintech firms, traditional financial institutions, and insurance providers must adhere to stringent compliance requirements to avoid regulatory penalties. They need to ensure they are interacting with genuine users, not fraudsters. To stay competitive, these institutions must act swiftly, which can sometimes lead to fraudulent profiles slipping through the cracks. Implementing a machine learning system can provide invaluable insights to distinguish between legitimate and fake user profiles.

Fraud Detection Machine Learning

Tackling Bonus Abuse and Multi-Accounting

Online gaming platforms and betting sites must ensure their players are genuine while also offering enticing rewards to new customers. This dual objective creates opportunities for fraudsters to engage in multi-accounting, claiming signup bonuses, and collusive play. Machine learning systems can analyze data to identify suspicious user behavior, detecting poker bots, cheating players, and low-quality traffic from dishonest affiliates.

Fraud Detection Machine Learning

eCommerce Fraud Prevention for Online Retail

Scrutinizing thousands of transactions can be a daunting task for eCommerce fraud managers. Machine learning can help identify the reasons why certain transactions weren't initially flagged as fraudulent. Leveraging machine learning can reveal which products are frequently targeted by fraudsters. It can also point out high-risk shipping information, and which card payments should be blocked to reduce chargeback rates.

Fraud Detection Machine Learning

Streamlining Gateway Security

Manually reviewing every transaction is impractical for payment gateways, especially when speed is critical. Processing thousands of transactions quickly makes human intervention virtually impossible. Machine learning engines can serve as a fraud monitoring analytics system and be trained to detect fraudulent transactions and prevent chargeback costs (specifically, for “non-authorized” chargebacks).

Implementation Guide: Getting Started with ML Fraud Detection

To get started, you will need as much transaction data as possible. This will establish a baseline for acceptable customer behavior. If your data set is too small for accurate learning, some providers will create “starter sets” of data from businesses similar to yours.

Next, the machine learning fraud detection system will pull specific data points from each transaction and add them to the model. This may include personal customer information, order and payment details, the location and network of the order, and so on. For a fraud detection model, all this information will need to be labeled as “good” or “bad.”

You now have the raw data to build your model. However, you still need to create an algorithm that helps the machine recognize the difference between “good” and “bad” transactions. Basically, you have to teach it the parameters for determining the legitimacy of a transaction.

Step #1  |  Data Collection

The first step is to gather data from various sources, such as transactional data, user behavior, and historical fraud cases. This data forms the basis for training and evaluating machine learning models.

Step #2  |  Data Preprocessing

Raw data needs to be cleaned and preprocessed to ensure that it is suitable for machine learning algorithms. This step may involve handling missing values, removing outliers, and converting categorical variables into numerical values.

Step #3  |  Feature Engineering

This is the process of extracting relevant features or variables from the raw data. Features can be basic attributes (e.g., transaction amount, time, and location) or more complex, derived attributes that capture specific patterns indicative of fraud.

Step #4  |  Data Splitting

The preprocessed data is divided into training and testing sets. The training set is used to build the model, while the testing set is reserved for evaluating its performance.

Step #5  |  Model Selection

There are various machine learning algorithms suitable for fraud detection, including logistic regression, decision trees, random forests, support vector machines, and neural networks. The choice depends on the problem's nature, data characteristics, and desired performance.

Step #6  |  Model Training

The chosen algorithm is “taught” based on the training dataset, where it learns to identify patterns and relationships between input features and the target variable (fraud or non-fraud).

Step #7  |  Model Evaluation

The model's performance is assessed on the testing dataset using evaluation metrics such as precision, recall, F1 score, and area under the ROC curve (AUC-ROC). These metrics help determine the model's ability to correctly classify fraudulent and non-fraudulent transactions.

Step #8  |  Hyperparameter Tuning

The model's performance may be improved by adjusting its hyperparameters, which are settings that influence the learning process. This step typically involves a search over a range of hyperparameter values to find the combination that yields the best performance.

Step #9  |  Model Deployment

Once the model has been trained and evaluated, it can be deployed into a production environment, where it will monitor and analyze transactions in real-time. When the model detects a potentially fraudulent transaction, it can flag it for further investigation or automatically block the transaction.

Step #10  |  Model Maintenance

Fraud patterns evolve over time, so it's crucial to regularly update the model with new data and retrain it to maintain its effectiveness. This process may involve continuous monitoring of the model's performance, incorporating new fraud cases, and adjusting hyperparameters as needed.

Are There Any Disadvantages to Adopting Machine Learning?

Fraudsters work tirelessly to find new ways to subvert the system. For example, finding new ways to mimic typical customer behavior. This can make any fraud indicators much more subtle and harder to recognize. There’s also the fact that machines are only as good as the input they have. 

Any bad data can impact the algorithm results. And since transaction info is fed back into the model, it can cause serious issues over time. For example, if your system misidentifies a friendly fraud incident as genuine criminal fraud, that skews the decisioning matrix. Inaccurate data leads to bad decision making, so the ML system will keep making the same mistake over and over.

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Despite the system’s benefits, there are instances where traditional manual reviews may be more suitable than automated systems:

  • Limited Control: “Black box” machine learning engines can occasionally make errors without detection. This lack of transparency and control can be concerning for businesses, particularly when these mistakes have significant consequences.
  • False Positives: Because rules only allow “yes” or “no” decisions, it’s not uncommon for legitimate orders to get marked as fraud. This is a serious concern, as false declines cost merchants $443 billion every year.
  • Absence of Human Insight: Understanding the underlying reasons behind suspicious user actions can sometimes require human intuition and psychological analysis. This is something that automated systems may struggle to replicate.
  • Friendly Fraud: Since first-party abusers typically exhibit normal, non-fraudulent behavior patterns, it becomes difficult for machine learning algorithms to distinguish between genuine and friendly fraud transactions.
  • High-Value Transactions: Manual reviews can be more reliable for high-stakes transactions. In these cases, human reviewers can provide an additional layer of scrutiny to verify the legitimacy of the transaction and minimize the risk of fraud.
  • Implementation Challenges: Overhauling your existing rules-based fraud detection system and replacing it with a machine learning model can be cumbersome, time-intensive, and expensive. Development, integration, testing, and staff training can cost thousands. So, failed implementation is a real (and costly) risk.
  • Ongoing Considerations: The work’s not over even after your new machine learning model is up and running. Ongoing data storage, testing, fine-tuning, retraining, and performance monitoring obligations will require significant amounts of time, attention, money, and specialized expertise.

While AI-driven fraud prevention offers numerous advantages, there are situations where manual reviews remain the preferred choice. Balancing the use of technology with human expertise can help businesses effectively mitigate risks and maintain a robust fraud prevention strategy

The Proper Role of Machine Learning Technology

Machine learning has an important role to play in ensuring data integrity and identifying post-transaction threats like friendly fraud, return fraud, and cyber shoplifting. That role is very different from conventional fraud detection machine learning, though.

Using machine learning for more intelligent chargeback source detection lets you:

  • Look beyond reason codes to find the true sources of chargebacks
  • Be more proactive about future disputes
  • Identify new revenue opportunities
  • Reduce fees, overhead, and other costs
  • Eliminate false positives and accept more transactions

An end-to-end solution powered by machine learning fraud detection technology is the only way to see true revenue recovery and sustainable growth.

FAQs

How can machine learning detect fraud?

The program tests incoming information to see if it either contradicts or reinforces an existing algorithm, then adjusts accordingly. The more data the machine receives, the more reliable its predictions will be.

What are the three different real-time machine learning fraud detection methods?

Three common models for real-time machine learning fraud detection include anomaly detection, which is aimed at detecting data outliers that deviate from normal patterns, as well as supervised and unsupervised machine learning. The former involves an algorithm trained to recognize patterns and determine outcomes, while the latter relies on an algorithm that processes unlabeled data to detect hidden relations between data points.

How can banks use machine learning for fraud detection?

Machine learning fraud detection offers advantages over traditional, rules-based fraud solutions as well. Legacy systems depend on absolute “yes/no” answers. This means someone must constantly monitor, review, and update the technology manually. A fraud detection machine learning model, however, is designed to adapt to new information on its own.

How does machine learning work in fraud detection?

Once trained and deployed, machine learning fraud detection models analyze your fraud surface for anomalies. These are events that deviate significantly from normal login, checkout, or purchase patterns. Upon detecting an outlier, your fraud detection model may forward the activity for manual review or block the transaction or user outright.

What is the best machine learning algorithm for fraud detection?

Because each fraud environment is unique, no single machine learning algorithm can be considered “best.” That said, random forests, neural networks, extreme gradient boosting (XGBoost), logistic regression, and decision trees have shown to be effective for fraud detection.

Which algorithm is used for fraud detection?

Algorithms like neural networks, random forests, and extreme gradient boosting (XGBoost) are popular choices for fraud detection applications.

Can deep learning be used for fraud detection?

Yes, deep learning techniques like convolutional neural networks (CNNs), recurrent neural networks (RNNs), generative adversarial networks (GANs) and autoencoders are especially useful in detecting complex fraud patterns.

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