WikiLeaks has released the latest instalment in the #Vault7 series, detailing two apparent CIA malware frameworks dubbed ‘AfterMidnight’ and ‘Assassin’ which it says target the Microsoft Windows platform.

Earlier today, our products detected and successfully blocked a large number of ransomware attacks around the world. In these attacks, data is encrypted with the extension “.WCRY” added to the filenames.

Our analysis indicates the attack, dubbed “WannaCry”, is initiated through an SMBv2 remote code execution in Microsoft Windows. This exploit (codenamed “EternalBlue”) has been made available on the internet through the Shadowbrokers dump on April 14th, 2017 and patched by Microsoft on March 14.

Thousands of patients across England and Scotland have been in limbo after an international cyber-attack hit the NHS, with many having operations cancelled at the last minute.

Senior medics sought to reassure patients that they could be seen in the normal way in emergencies, but others were asked to stay away if possible.

According to one junior doctor who works in a London hospital, the attack left hospitals struggling to care for people. “However much they pretend patient safety is unaffected, it’s not true. At my hospital we are literally unable to do any x-rays, which are an essential component of emergency medicine,” the doctor told the Guardian.

Update 4: According to experts tracking and analyzing the worm and its spread, this could be one of the worst-ever recorded attacks of its kind. The security researcher who tweets and blogs as MalwareTech told The Intercept “I’ve never seen anything like this with ransomware," and "the last worm of this degree I can remember is Conficker.” Conficker was a notorious Windows worm first spotted in 2008; it went on to infect over nine million computers in nearly 200 countries.