🎯 Preamble: Don't Panic, Act!

Is your PC showing signs of infection? Slowdowns, unwanted pop-ups, inaccessible files? Breathe. This complete guide, enriched with the latest cybersecurity trends for 2025, gives you the keys to understand, analyze, and solve the problem on Windows, macOS, and Linux.

In 2025, cyber threats are evolving rapidly with the rise of AI-driven attacks, fileless malware (living-off-the-landAttack technique using legitimate system tools to avoid detection), vulnerabilities in supply chains, and infections via IoT. These threats affect all systems, including via connected mobile devices (scan them with tools like Malwarebytes for Android/iOS).

With the right methods, including post-cleaning monitoring and advanced tools, you will regain control and strengthen your defense.

📈 Chapter 1: Threats Infographic

Attack evolution by OS (2023–2025)

Malware distribution by OS (2025)

🧠 Chapter 2: Understand the Enemy – Malware Types

📝 Chapter Introduction

Before acting, understand your adversary. This chapter presents the different malware families, their modes of action, and their danger levels. Knowing the enemy is the first step toward effective defense. In 2025, threats include innovations like AI-driven attacks and malware-free (living-off-the-land) techniques.

🎭 The Cybercriminal Family

🔍 Chapter 3: How Did the Infection Occur?

📝 Chapter Introduction

Understanding how the malware infiltrated your system is crucial to avoid reinfection. This chapter explores the most common attack vectors and how to recognize them, including supply chains and IoT.

🎣 The 7 Dreaded Scenarios

🚨 Chapter 4: The 5 Life-Saving Actions – Emergency Procedure

📝 Chapter Introduction

When facing an infection, every second counts. This chapter details the step-by-step procedure to immediately follow to contain the threat and limit damage.

# Cut all connections:
- Wi-Fi/Ethernet: OFF
- USB devices: unplugged
- Network sharing: disabled

🔄 Chapter 5: Restoration and Strengthening

When the graphical interface and recovery mode fail, use the terminal or native tools:

# Timeshift command (Linux Mint, Ubuntu…)
sudo timeshift --check
sudo timeshift --list-snapshots
sudo timeshift --list-devices
sudo timeshift --restore --snapshot '2025-08-15_12-00-00'
sudo reboot

Snapper (openSUSE/Btrfs)

# At startup, in GRUB, choose Advanced options for openSUSE → Rollback to Snapshot
# Select your snapshot and remember its number.
# At GRUB prompt:
snapper rollback <snapshot_number>
# Restart and confirm in session:
sudo snapper rollback <snapshot_number>
sudo reboot

NixOS

sudo nixos-rebuild switch --rollback
sudo reboot

💻 Chapter 6: Advanced Solutions by Operating System

📝 Chapter Introduction

Each operating system requires a specific approach. This chapter details the most effective tools and methods for Windows, macOS, Linux and NixOS. For persistent cases, consult an expert or report to ANSSI/CERT-FR.

🛡️ Essential Tools Comparison Table

🚀 Bootable USB Guide

🛡️ Chapter 7: Prevention – Never Get Hacked Again

📝 Chapter Introduction

The best defense against malware is prevention. This chapter gives you all the keys to strengthen your security and avoid future infections, including post-cleaning.

🛡️ The Digital Survival Kit

📊 Numbers That Should Convince You

❓ FAQ – Frequently Asked Questions by Chapter

🧩 Final Quiz: Test Your Vigilance

🎯 Conclusion: Your Immediate Action Plan

📚 Verified Sources

Article updated in September 2025 with latest threats and solutions. Always verify information with official sources.