Charities are being used by fraudsters to persuade computer users to click on a link that then encrypts all their files in seconds, allowing the criminals to demand a payment for unlocking them.

The fraudsters have used charity Koestler Trust, lying to victims with phishing emails that they owe it money and telling them to click on a link to see the invoice. Those that do are then connected to the encrypting malware, called Maktub which initially demands a ransom of around £400, rising to around £550 if not paid after three days.The phishing emails are given extra credibility by accurately including the victim’s address.

Computer users are advised to never open emails that claim they owe, or are owed money. The UK’s central body for reporting cyber crime is Action Fraud at web: actionfraud.police.uk, helpline on tel: 0300 123 2040