Ransomware

Ransomware is malicious software designed to block access to a computer system or files, usually by encrypting them, and to demand a ransom in exchange for unlocking them. This type of malware aims to extort money from its victims, whether individuals, government agencies, or businesses. Ransomware attacks have multiplied in recent years, causing significant losses and disrupting the operations of many organizations for long periods.

How ransomware works

Ransomware usually enters a system through an infected attachment, a malicious link, or by exploiting an unpatched software vulnerability. Once executed, it encrypts the files stored on the device or network, then displays a ransom demand, often written in English, along with precise payment instructions, usually in cryptocurrency.

Some ransomware goes further by threatening to publicly disclose the stolen data (known as doxware), while others simply block access to the system without encryption. Unlocking, if it happens at all, depends on the attackers handing over a decryption key after payment – with no guarantee whatsoever.

Types of ransomware

Ransomware comes in several variants, depending on how it operates and its impact:

• Crypto ransomware: Encrypts the user's files, making them unusable without the decryption key.
• Locker ransomware: Blocks access to the entire system, preventing any use, including of the interface.
• Doxware (or leakware): Combines encryption with the threat of disclosing sensitive data to put pressure on the victim.
• Ransomware-as-a-Service (RaaS): An organized cybercrime model in which malicious groups rent out ransomware to affiliates in exchange for a share of the ransoms collected.

Consequences of ransomware

A ransomware attack can have serious technical, financial, and legal repercussions:

• Data loss: Without a backup, encrypted files are often unrecoverable.
• Business interruption: Affected systems can be out of service for several days, or even weeks.
• High financial cost: In addition to the potential ransom, the costs of recovery, expert analysis, and compliance are significant.
• Reputational damage: The disclosure or loss of data can tarnish the organization's image.
• Regulatory obligations : If personal data is compromised, notification to the CNIL may be required.

Preventing and protecting against ransomware

The best defense against ransomware relies on a rigorous cybersecurity strategy and a solid backup policy.

Here are the main preventive measures:

• Regular software updates: Patch the security flaws exploited by ransomware.
• Use of effective antivirus software: Scan incoming files and block suspicious executions.
• Email filtering: Detect phishing messages, a frequent vector for ransomware.
• User awareness: Train employees in good practices and warning signs.
• Regular data backups: Keep recent copies of files on disconnected media or in offsite backup storage.
• Limiting privileges : Restrict access rights to critical resources.
• Controlling remote access: Secure VPN connections and disable unused access.
• Security audit: Identify system weaknesses before they are exploited.

What to do in the event of a ransomware attack?

If you are the victim of ransomware, certain steps must be followed rigorously:

• Immediately disconnect the equipment from the network to limit the spread.
• Do not pay the ransom: Payment does not guarantee data recovery and finances illegal activities.
  Preserve the evidence: Screenshots, activity logs, encrypted files… these elements are essential for investigators.
• File a complaint with the police, the gendarmerie, or the public prosecutor.
• Call on a cybersecurity professional to analyze the incident, eradicate the threat, and restore the systems.
• Notify the CNIL if personal data has been compromised.
• Restore the data from a reliable, uninfected backup.
• Analyze the exploited vulnerability to prevent another attack.

Conclusion

Ransomware is a growing and particularly destructive threat in the cybersecurity landscape. It can paralyze entire systems, compromise sensitive data, and cause severe financial losses. To protect against it, user vigilance must be combined with robust technical measures, in particular an offsite backup policy such as the one offered by Kiwi Backup.

Investing in an automated and secure backup solution is today one of the most effective ways to minimize the impact of an attack and ensure the resilience of your IT infrastructure.