Ransomware is malicious software that encrypts a business's files or locks its systems and demands payment for their return. Many attacks also steal data first and threaten to publish it.
It usually arrives through phishing emails, stolen passwords, unpatched software or exposed remote access. Once inside, it spreads across the network, encrypts data and leaves a ransom note.
For retailers and hospitality venues the impact can be severe: tills, ordering and stock systems stop and trading halts. Recovery depends heavily on whether clean, tested backups exist.
Protection is layered: keep systems patched, use multi-factor authentication, train staff to spot phishing, restrict administrator rights, run endpoint protection and keep offline or immutable backups. Have an incident plan so everyone knows who to call.