A suspicious email, a web page that loads strangely, software that slows down the machine for no apparent reason: most cyberattacks start with a seemingly trivial detail. Protecting your computer is no longer just about installing antivirus software. In France, nearly one in two residents has already been informed that their personal data has been compromised, according to figures reported by Cybermalveillance.gouv.fr. Cyber threats now target both your credentials and your files.
Personal data leaks: the threat that surpasses the classic virus
Have you ever received an SMS from your bank asking you to confirm a transaction you never made? This type of attempt often relies on information stolen during massive leaks. The scenario is simple: a database from a merchant site or a public service is hacked, and then your name, email address, and sometimes bank details are sold on underground markets.
The proportion of French people affected by these leaks has risen from 30% to 45% in just one year. This figure explains the rise of so-called “targeted” attacks: personalized phishing replaces generic spam. A hacker who knows your name, your telecom operator, and your address can craft a fake email that is much more convincing than a message filled with mistakes.
To check if your information has already leaked, online tools like those listed on the Viruslab webpage can analyze the threats associated with your accounts and help you better understand your actual exposure.
Online account security: protecting your digital identity on your computer
Installing a firewall and antivirus remains useful, but the majority of recent intrusions no longer exploit a technical flaw in the operating system. They exploit a more fragile link: your login credentials.
Let’s take a concrete example. You use the same password for your email and for an online shopping site. That site suffers a leak. The hacker then automatically tests your email/password combination on dozens of other services. In just a few minutes, they gain access to your email, and then to everything linked to it (social networks, bank accounts, cloud storage).
Three concrete measures significantly reduce this risk:
- A unique password for each service, of at least 12 characters, mixing uppercase letters, lowercase letters, numbers, and special characters. A password manager (like KeePass or Bitwarden) helps avoid having to memorize them all.
- Enabling two-factor authentication wherever it is offered. This mechanism adds verification via SMS, app, or physical key. Even if your password is stolen, access remains blocked without this second factor.
- Regularly checking active logins on your main accounts (email, banking, social networks). Most of these services offer a login history in their security settings.
Updates and software: what truly protects your Windows or macOS system
Operating system updates are not just for adding features. Each patch released by Microsoft or Apple closes a vulnerability that attackers could exploit. Delaying a security update by a few weeks is like leaving a door open all that time.
Enabling automatic updates is the most cost-effective technical gesture for an individual. This applies to the system (Windows, macOS, Linux), but also to the web browser and installed software. An outdated browser remains one of the most common infection vectors.
On the software side, the rule is to limit the number of installed programs to the strict minimum. Each additional application increases the attack surface. Only download from the official publisher’s sites or from the app stores integrated into the system. Free software found on an unknown site may carry malware that your antivirus cannot detect for several days.
Free or paid antivirus: what level of protection to choose
Windows natively includes Microsoft Defender, which provides adequate protection against common threats. For typical home use (browsing, email, office work), this solution is sufficient in most cases.
A paid antivirus is justified when you handle sensitive data, when multiple people share the same computer, or when you regularly download files from various sources. Paid suites generally add a strengthened anti-phishing filter, a VPN, and an integrated password manager.
File backups: the safety net against ransomware
A ransomware encrypts all your files and demands a ransom to unlock them. Even with up-to-date antivirus software, no protection is 100% reliable. Regular backup remains the only guarantee of recovering your data after a successful attack.
The simplest method is to copy your documents to an external hard drive that you then disconnect from the computer. A ransomware cannot encrypt a disconnected device. Complementing this local copy with a cloud backup adds protection against theft or fire.
Why disconnect the drive after copying? Because modern ransomwares scan all connected devices, including USB drives and network drives. A device that is permanently connected will be encrypted along with everything else.
- Schedule a weekly backup for your work documents and photos.
- Test the restoration at least once: an unreadable backup is useless.
- Keep at least two copies on different media (external drive and cloud, for example).
The cybersecurity of a computer relies less on a miracle tool than on a few habits maintained over time. Unique passwords, timely updates, disconnected backups: these three combined practices neutralize the vast majority of attack scenarios that an individual is exposed to today.
