Ransomware

Ransomware is a type of malicious code that encrypts a victim's files or locks access to an entire system, then demands payment — usually in cryptocurrency — in exchange for the decryption key. Ransomware attacks are one of the most serious threats to businesses and institutions because they can paralyze operations, encrypt databases and networked backups, and cause financial damage running into the millions.

How ransomware works

A typical attack unfolds in several stages:

1. Infection — the code enters the system, most often via phishing (an email attachment or link), a software vulnerability (exploit) or remote access with stolen credentials.
2. Spreading — the malware moves laterally across the network, escalates privileges and locates valuable data and backups.
3. Encryption — files are encrypted with a strong algorithm, and the key stays solely with the attacker.
4. Ransom demand — a message appears with payment instructions; increasingly, double extortion is used — a threat to leak the stolen data.

Modern campaigns run on a Ransomware-as-a-Service model, where the authors rent the tool to other criminals for a cut of the profits.

Ransomware in practice — defense

Effective defense against ransomware relies on several layers:

• Backups — regular, network-isolated, ideally immutable backups the malware cannot overwrite; this is the only sure path to recovery without paying.
• Patching and segmentation — fixing vulnerabilities and splitting the network limit spread.
• Firewall and access control — a firewall, the principle of least privilege and multi-factor authentication make entry harder.
• Continuity plan — defined RTO and RPO targets set how fast and with how much data loss the organization returns to operation.

Tested, isolated backups remain the single most important element of defense — without a proven backup, recovering data after an attack can be impossible.