FREE COURSE / SELF-PACED LEARNING

Infostealers: The Modern Key to Your Digital Kingdom

Understand infostealer risks and their security implications with this free, self-paced cyber threat course.

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Experience level
Beginner
Curriculum
5 modules · 10 lessons
Estimated reading
30 min
Language
English

Reading estimates use lesson text and an allowance for diagrams. Reflection, exercises and optional linked resources take additional time. These are estimates, not measured completion times.

KNOW WHAT YOU’RE WORKING TOWARD

What you’ll learn

  • Define infostealers and explain why they have become the primary threat in the modern cybercriminal ecosystem.

Is this the right course for you?

Who it’s for

Security learners examining credential and session-theft threats.

Scope and boundaries

Threat understanding and defensive interpretation. The course does not involve running malware or collecting live credentials.

How you’ll learn

Self-paced reading with explanatory diagrams and linked resources. Reflection and optional resource study take additional time.

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.

FOLLOW THE LEARNING PATH

Course curriculum

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.

  1. The Scale of the Threat: 11.1 Million Devices and 3.3 Billion CredentialsBegin your journey by understanding the massive scale of the infostealer epidemic and why your credentials are now the most valuable currency for cybercriminals.7 min reading
  2. How Credentials Became the New GoldUnderstand why credentials have become the most valuable commodity in the cybercriminal economy5 min reading

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.

  1. How Infostealers Reach the DeviceFollow the common delivery paths that place infostealer malware on a device and learn where prevention can interrupt them.3 min reading
  2. What Happens After ExecutionUnderstand how an infostealer profiles the device, locates valuable data, and attempts to avoid detection.2 min reading

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.

  1. Exfiltration Channels and Their SignalsCompare how infostealers move collected data and what defenders can observe at each channel.3 min reading
  2. Detect and Investigate Data TheftBuild a safe investigation workflow for suspected infostealer exfiltration and distinguish containment from eradication.2 min reading

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.

  1. The Stolen-Data Supply ChainTrace stolen data from infection logs to brokers, access buyers, and follow-on abuse.2 min reading
  2. From Credential Theft to Account TakeoverRecognize follow-on abuse patterns and prioritize response to stolen sessions, accounts, and privileged access.2 min reading

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.

  1. Prevent Infostealer InfectionBuild practical personal and organizational controls that reduce delivery, execution, and credential exposure.2 min reading
  2. Respond, Recover, and LearnUse a repeatable response workflow after suspected infection and turn lessons learned into stronger controls.2 min reading

Sources and editorial review

Reviewed by Threat Intelligence Lab

Sources linked in the lessons provide context and further reading. Check the original documentation for current platform behavior and requirements.

About this learning content: Courses, lessons, assessments, explanations and illustrations may be created with the help of artificial intelligence. We review and check the material and do our best to avoid incorrect or outdated information, but mistakes, omissions or ambiguous questions may remain. Please verify information before relying on it for professional, security, legal or operational decisions. Read the full notice or report an issue.