Ransomware is a type of malicious software that encrypts files on an infected computer or server and demands a ransom payment to restore access.

 Ransomware is a type of malicious software that encrypts files on an infected computer or server and demands a ransom payment to restore access. The term combines “ransom” and “software,” and it represents one of the most serious and fast-spreading forms of cybercrime. Infection methods vary: malicious email attachments and links, phishing websites, software vulnerabilities, and unauthorized access through remote desktop connections are common entry points. Once infected, personal photos, documents, and business data are encrypted with strong algorithms, and the screen displays a message demanding payment—often in cryptocurrency such as Bitcoin—within a set deadline to obtain a decryption key. Failure to pay can result in threats to delete or publicly leak data, a scheme known as “double extortion.” Notable examples include CryptoLocker, WannaCry, and Ryuk, which have caused massive damage to companies, municipalities, and hospitals worldwide.

Effective countermeasures include keeping operating systems and applications up to date, avoiding unverified attachments and suspicious links, using antivirus or advanced detection tools (EDR/XDR), limiting user privileges, and performing regular offline and cloud backups. If an infection occurs, the best immediate response is to disconnect the device from the network, report the incident to relevant authorities (such as police or cybersecurity agencies), preserve system logs, and seek expert recovery assistance. Paying the ransom is strongly discouraged, as there is no guarantee of data recovery and the funds may directly support criminal organizations. For this reason, many governments and international organizations emphasize reporting attacks and refusing payment as part of responsible cyber-incident management.