Ransomware: How to protect a company from ransomware

Ransomware is one of the biggest threats to companies of all sizes. Attackers encrypt your data and demand a ransom for its restoration. Small businesses are frequent targets because they have weaker security than large corporations. This article will guide you on how to defend yourself and what to do if the worst happens.

What is ransomware and how does it work

Ransomware is malicious software that, after infiltrating a computer or network, encrypts your files. Documents, spreadsheets, databases, photographs, everything becomes inaccessible. A message then appears demanding a ransom payment, usually in cryptocurrency, in exchange for a decryption key.

Modern ransomware often does not end with encryption alone. Attackers steal data before encrypting it and threaten to publish it. This is known as "double extortion" and is now a common tactic.

How Ransomware Works

• Phishing emails: The most common route. An employee opens an attachment or clicks a link in a fraudulent email.
• Software vulnerabilities: Outdated systems and applications have security vulnerabilities that attackers will exploit.
• Unconventional approach (RDP): Insecurely configured Remote Desktop is an open door for attackers.
• Infected USB drives: Lower risk, but still realistic, especially in environments with high staff turnover.

Prevention: How to avoid a breakdown

Rule number 1: Deposits, deposits, deposits

A proper backup strategy is your strongest weapon. Stick to the 3-2-1 rule: three copies of data, on two different media, with one copy off-site (cloud or offline). Crucially, the backup must be isolated from the main network, if ransomware encrypts your backups as well, they are useless.

Regularly test restoration from backups. A backup from which data cannot be restored is not a backup.

System and software update

Most successful attacks exploit known vulnerabilities for which a fix already exists. Regular updates of Windows, Office, browsers and other software are basic hygiene. Automatic updates should be enabled on all workstations.

Antivirus and EDR

A classic antivirus is no longer sufficient on its own. Modern protection is called EDR (Endpoint Detection and Response) and can detect suspicious behaviour, not just known viruses. Solutions such as ESET PROTECT, Microsoft Defender for Business or CrowdStrike offer comprehensive protection including centralised management.

Staff training

Technology alone is not enough. Employees must know how to recognise a suspicious email, why not to click on unknown links and who to report a suspicious message to. Short regular training (for example once a quarter) significantly reduces the risk.

Restrictions on access rights

Not every employee needs access to everything. The "least privilege" principle means that an accountant has access to accounting data but not to technical documentation, and vice versa. If ransomware infects one workstation, restricted permissions prevent it from spreading to other parts of the network.

What to do if an attack occurs

Even with the best prevention, attackers may succeed. It is important to have a plan:

1. Immediately disconnect the infected computer from the network., disconnect the power cable and Wi-Fi. The aim is to prevent spread to other devices.
2. Do not pay a buyout fee.: payment guarantees nothing and funds further attacks.
3. Contact your IT administrator: will assess the extent of the damage and commence restoration.
4. Keep your receipts Do not delete anything; a screenshot of the message requesting a buyout price may be useful for the police.
5. Report an incident: the Police of the Czech Republic and NUKIB (National Office for Cyber and Information Security).
6. Restore data from backups: which is why these deposits are so important.

How much does a ransomware attack cost a company?

According to Czech statistics, the average compensation claimed by small businesses amounts to hundreds of thousands of Kč. However, the actual costs are much higher: downtime, data loss, reputational damage, and legal consequences. One day without IT can cost a company tens of thousands of Kč in lost productivity.

Investing in prevention - backups, monitoring, updates, training - costs a fraction of what resolving a single successful attack will cost you.

Summary

Ransomware is not a matter of "if" but "when". With good backups, updated systems, modern protection and trained employees, you significantly reduce the likelihood of a successful attack. And if one occurs despite this, you will be ready to recover quickly.