Cryptowall 4.0 – the newest version of the world's worst Ransomware – has surfaced in the Nuclear exploit kit, one of the most potent exploit kits available in the underground market for hacking into computers.

Ransomware threat has emerged as one of the biggest threats to internet users in recent times. Typically, a Ransomware malware encrypts all files on victim’s computer with a strong cryptographic algorithm, then demand a ransom to be paid in Bitcoin. Cryptowall is currently among the most widespread and sophisticated family of Ransomware backed by a very robust back-end infrastructure.

A sophisticated cyber-crime campaign is leaving millions of people vulnerable to having malware installed on their computers simply by visiting high profile websites.

The campaign is using the fast-growing method of 'malvertising' to spread a pernicious form of malware called ransomware, which encrypts all the files on the hard drive of a victim's computer, and if the victim doesn't pay a ransom by deadline, those files are lost forever. The researchers were even able to estimate how much money the criminals were earning on a daily basis as the ransoms are charged in bitcoin, meaning all payments are traceable via the public blockchain.