Ransomware: definition, how it works and how to protect it

Picture the scene: you arrive at the office on a Monday morning, coffee in hand, ready to take on the world (or at least your to-do list). But now it's the drama. Your computer screen displays a threatening message: all your files are blocked, inaccessible. To recover them, strangers ask you for a nice sum in cryptocurrency.

Congratulations, you've just met a Ransomware.

If you think it only happens to others, think again. Even tech giants and the platforms we use every day are in the crosshairs. Recently, the news has highlighted how cybercriminals are exploiting popular services like Discord to spread malware or exfiltrate data, showing that no one is really safe.

Don't panic! This type of malicious software, also called “ransomware” in good French, is unfortunately one of common cyber attacks the most feared by businesses. But as with any movie villain, knowing their plan and weaknesses is the best way to beat them.

So take a deep breath. We explain everything about this digital hacker, with less jargon and more solutions.

What is ransomware?

Ransomware, or ransomware, is a type of malware whose purpose is to take your data hostage and demand a ransom from you to return it to you. He's a bit of a bank robber in the digital world, except that instead of emptying your coffers, he locks up your most valuable files.

The premise is simple: cybercriminals infiltrate your computer system, encrypt your data to make it unreadable, and leave you a message with payment instructions. If the victim pays the ransom, they (in theory) receive the decryption key to recover their files.

This criminal business is so lucrative that it even gave birth to RaaS (Ransomware-as-a-Service). No, it's not a new streaming service. It's a model where hackers develop ransomware and “rent” it to other cybercriminals who are less good at coding, in exchange for a percentage of the ransoms collected. The uberization of crime, in short.

How does ransomware work? The main steps

A ransomware attack usually takes place in three acts, like a bad thriller.

Act 1: Discreet Infiltration

This is when the malicious software enters your system. The most common techniques are:

• Phishing (phishing) : An apparently legitimate email (an invoice, a delivery notification...) containing a malicious attachment or a tricked link. A click of inattention, and the door is open.
• Social engineering : Psychological manipulation techniques to trick you into disclosing information or performing a dangerous action.
• Exploiting security breaches : Hackers scan networks looking for unfixed flaws in software, server, or operating system in order to get in.

Act 2: Silent Encryption

Once inside, the ransomware gets to work. It identifies important files (documents, databases, photos...) on your computer and, potentially, on the entire company network. He then uses a encryption key complex to lock them one by one. At this point you don't notice anything yet. The software is designed to be as discreet as a ninja.

Act 3: The ransom demand

The final bouquet. The ransomware has finished its work and is finally coming to light. A message appears on the screen of the infected device. It tells you that your files are encrypted and gives you an ultimatum: pay a certain amount (often in Bitcoin to guarantee the anonymity of the attackers) before a deadline, otherwise your data will be deleted or disclosed on the Dark Web.

What are the consequences of a ransomware attack?

The consequences of a ransomware attack go far beyond simply paying a ransom. For a business, the impact can be devastating.

• Activity paralysis : More access to customer files, accounting, ongoing projects... The entire company is forced to come to a standstill.
• Colossal financial losses : Between the cost of the ransom (if paid), the loss of turnover due to inactivity, and the costs of restoring the systems, the bill can quickly reach Millions of dollars.
• Reputation damage : Announcing to your customers and partners that their data has been compromised is a major blow to trust and your brand image.
• Sensitive data leak : This is the “double extortion” trend. Not only do hackers encrypt your data, they steal it first and threaten to publish it. We saw it recently with a data leak at Discord, where internal information was put up for sale on the dark web. Even without direct encryption, the threat of disclosure serves as a blackmail tool, a tactic typical of ransomware groups.

How can you effectively protect yourself against ransomware?

Good news: turning into an impregnable fortress is not that complicated. Ransomware protection is based on a mix of common sense, best practices, and the right tools.

1. Raise awareness among your teams : Humans are often the first weak link. Train employees to recognize phishing emails and to be wary of suspicious attachments. The golden rule: when in doubt, don't click!
2. Make regular backups : It's your digital life insurance. Back up important data regularly to external media or to a cloud that is disconnected from your main network. If you are affected, you will be able to restore your files without giving in to blackmail.
3. Update your systems : Systematically apply security updates for your software, operating system, and antivirus software. They fix the flaws that hackers love to exploit.
4. Use the right tools : A powerful antivirus, a well-configured firewall, and an email filtering solution are essential. Remember to equip yourself with the right ones cybersecurity tools for optimal protection.
5. Limit access rights : Each user must have access only to the data and applications necessary for their mission. So if an account is compromised, the damage will be limited.

How do you react in the event of a ransomware attack?

If the worst happens, here's what to do.

1. Isolate the infected machine : Unplug the computer from the network immediately (remove the Ethernet cable, turn off the Wi-Fi) to prevent the ransomware from spreading to other devices.
2. Don't pay the ransom : This is the recommendation of all cybersecurity agencies. Paying doesn't guarantee you'll get your data back, and it funds the crime industry.
3. Contact experts : Call on your IT department or an incident response specialist. They will help you assess the situation and eradicate the malware.
4. File a complaint : File a complaint with the gendarmerie or the police and report the attack on the government platform cybermaliciance.gouv.fr.
5. Restore and rebuild : Once the threat is eliminated, you can restore your data from your healthy backups and completely clean the affected systems.

Frequently asked questions about ransomware

What is the difference between ransomware and computer viruses?

It's a bit like comparing a kidnapper and a vandal. A typical virus seeks to spread and damage a system. One Ransomware, for his part, does not aim to destroy: he has a business model. He Encrypt files to make them unusable and require a Ransom in exchange for the key of decryption.

Do you have to pay a ransom in the event of a ransomware attack?

The tricky question! In the face of panic, the temptation to give in to blackmail is great. However, the unanimous response from experts is: No, no and no.

Paying the ransom is:

• Encourage cybercriminals to continue their dirty business
• Take the risk of never receiving the decryption key (yes, there is no guarantee for thieves).
• Identify yourself as a “good payer” target and be exposed to future attacks.
• Expose yourself to prosecution. In France, the financing of criminal activities is punishable by up to 5 years ofimprisonment and a fine of 375,000 euros. It's expensive to click.

Who to contact in case of ransomware?

1. Your IT service provider or cybersecurity specialist (like _rzilient, at random!).
2. The platform cybermaliciance.gouv.fr, who will connect you with professionals and guide you.
3. The forces of law and order to file a complaint (Police or Gendarmerie).

The best solution is still prevention. With _rzilient, you can choose to protect your business up front. By delegating to us the monitoring of your computer equipment and the management of your security, you no longer have to panic. We prevent these attacks for you, and if an incident occurs, we are already there to handle it.

‍