Infostealers: The Modern Key to Your Digital Kingdom
About this course
Infostealers have become the primary weapon of choice for cybercriminals. In 2025 alone, over 11.1 million devices were infected, with more than 3.3 billion credentials stolen. By early 2026, one family—Vidar—accounted for over 73% of all infections. This course takes you on a journey: you’ll start by understanding what infostealers actually are and why they’ve become so dangerous. You’ll walk through how they infect machines, what they steal, and how attackers exfiltrate the data—including the surprisingly common use of Telegram bots. You’ll learn about the underground economy where stolen credentials are traded, and finally, how to protect yourself and your organization. Each module answers the questions you’d naturally ask along the way, turning complex malware into something you can truly understand.
What you'll learn
- ✓ Define infostealers and explain why they have become the primary threat in the modern cybercriminal ecosystem.
Course content
Module 1: The Infostealer Epidemic: Why Your Credentials Are the New Gold
This module sets the stage. You will understand what infostealers are, why they have become the most popular malware among cybercriminals, and the massive scale of the problem. By the end, you will recognize why infostealers are the modern key to digital kingdoms.
The Scale of the Threat: 11.1 Million Devices and 3.3 Billion Credentials
Begin your journey by understanding the massive scale of the infostealer epidemic and why your credentials are now the most valuable currency for cybercriminals.
How Credentials Became the New Gold
Understand why credentials have become the most valuable commodity in the cybercriminal economy
Module 2: The Anatomy of an Infostealer
This module takes you inside the infostealer itself. You will learn how these malware families are built, how they infect machines, what happens after infection, and how they remain hidden from detection. You will understand the mechanics behind the threat.
How Infostealers Reach the Device
Follow the common delivery paths that place infostealer malware on a device and learn where prevention can interrupt them.
What Happens After Execution
Understand how an infostealer profiles the device, locates valuable data, and attempts to avoid detection.
Module 3: Data Exfiltration: How Stolen Data Gets Out
This module is where the journey gets real. You will learn how attackers extract stolen data from infected machines. We will focus on the surprisingly common use of Telegram bots for exfiltration, as well as other methods like HTTP, FTP, and email. By the end, you will see exactly how the data leaves the victim's device.
Exfiltration Channels and Their Signals
Compare how infostealers move collected data and what defenders can observe at each channel.
Detect and Investigate Data Theft
Build a safe investigation workflow for suspected infostealer exfiltration and distinguish containment from eradication.
Module 4: The Underground Economy: Where Stolen Data Goes to Die
This module takes you into the criminal underground. You will learn how stolen credentials are traded, sold, and used in follow-on attacks. You will understand the lifecycle of stolen data and the role infostealers play in the broader cybercrime ecosystem.
Module 5: Defending Your Digital Kingdom: How to Protect Against Infostealers
This module is your action plan. You will learn practical, effective strategies to prevent infostealer infections, detect them early, and respond if your organization is compromised. You will leave with a clear understanding of how to defend against the modern infostealer threat.