According to new research, the Cryptolocker malware has infected 250,000 PCs in just 100 days, earning more than $30m. The Cryptolocker ransomware works by encrypting a user’s hard drive and the only way to un-encrypt and regain access to the files is to pay a ransom within 72 hours.

If the ransom isn’t paid, the files are permanently locked with no way of ever accessing them again – though recently the criminals behind the malware have added a late payment option for a much higher price.

Research by Dell Secureworks Counter Threat Team (CTU) has shown that the cyber-criminals behind the CryptoLocker ransomware have successfully infected up to 250,000 systems and are mainly targeting victims in the US and UK.

The average ransom paid is around $300 (£183) and combining these figures with the number of systems infected equals a large sum of money.

Jarvis adds:

“Based on the duration and scale of attacks, [the gang behind CryptoLocker] also appear to have the established and substantial “real world” infrastructure necessary to ‘cash out’ ransoms and launder the proceeds.”