Ransomware is malicious software that encrypts victim’s files or entire systems and then demands a ransom for the decryption key.
It remains one of the most severe and disruptive threats in the modern IT landscape — capable of paralysing companies, public institutions, hospitals, and even entire cities.
What Is Ransomware?
Ransomware is a type of malware that blocks access to data or systems by encrypting them.
After infection, the victim receives a ransom note demanding payment (usually in cryptocurrency) in exchange for the decryption key.
Successful ransomware attacks cause data loss, prolonged downtime, and massive financial damage.
How Ransomware Works
Most infections occur via:
- Infected email attachments (e.g., “invoice.pdf.exe”)
- Fake software updates or cracked installers
- Malicious links and drive-by downloads on compromised websites
Once executed, the malware quietly encrypts files and displays the ransom demand.
Famous Ransomware Examples
- WannaCry (2017) – one of the largest global outbreaks, affecting hundreds of thousands of systems worldwide
- CryptoLocker – the first widespread ransomware that popularised file-encryption extortion
Both exploited unpatched operating-system vulnerabilities and missing security updates.
Warning Signs of a Ransomware Infection
Look out for these typical indicators:
- Unusual system slowdown or high CPU/disk activity
- Appearance of unknown files or folders
- Ransom note displayed on screen (often README.txt or .html)
- Files suddenly inaccessible or renamed with strange extensions (.locky, .crypt, .wannacry, etc.)
Prevention – How to Protect Against Ransomware
The best defence is proactive:
- Regularly create and test offline or immutable backups
- Keep all systems, applications, and firmware fully patched
- Deploy reputable endpoint protection (EDR/XDR) and anti-malware solutions
- Train employees to recognise phishing emails and suspicious links
- Segment networks and apply the principle of least privilege
Prevention is always cheaper than recovery.
What to Do If You Are Hit by Ransomware
- Immediately isolate the infected device(s) from the network
- Do NOT pay the ransom – there is no guarantee you’ll get your data back
- Engage your IT/security team or an incident-response specialist
- Restore data from a clean, recent backup
- Report the incident to CSIRT/CERT, law enforcement, and (if applicable) your regulator
Summary
Ransomware continues to be one of the most serious cyber threats today.
Understanding how it operates and implementing strong preventive measures is the foundation of any resilient organisation.
Don’t wait for an attack – start protecting your business now.
Email: biuro@wichran.pl
Phone: +48 515 601 621
Author: Piotr Wichrań – Court-appointed IT forensic expert, IT/OT cybersecurity specialist, licensed private investigator
@Informatyka.Sledcza