A massive cyber attack that has hit the NHS across the United Kingdom today has been blamed on Jeremy Hunt accidentally clicking on a pornographic film involving animals.

A senior source within Whitehall confirmed that the Health Secretary had opened an email sent by Foreign Secretary Boris Johnson ‘in good faith’ – within minutes computers across the entire NHS had been affected by one of the worst cases of ransomware that has ever been seen in Britain.

He said: ‘It is well-known that Boris likes the occasional prank, and it must have been a quiet day for him today as loads of us had an email from him with the subject ‘Urgent Diplomatic Business.’

‘There was a brief paragraph about the attached document containing ‘vital statistics related to the Brexit negotiation process,’ and the file was called ‘Brexit Negotiation Stuff.mp4′ – everyone except Jeremy realised that this was a video file format and not some sort of Powerpoint.’

‘We heard a massive shriek from Jeremy’s office, and I ran in there to see if he was OK. His screen was showing the opening credits from ‘Farmal Desires 7′ and a Dutch man with a huge moustache was doing something unspeakable to a small herd of Shetland ponies.’

‘By the time we had managed to close it, a pop-up appeared saying that the computer was locked and that a payment of $300 would be required to get the block removed.’

‘We then started getting phone calls from all over the country to say that the ransomware had appeared on other screens.’

A spokesperson for Boris Johnson confirmed that the prank email had been sent in ‘high spirits,’ and also that the Foreign Secretary has now been briefed on the dangers of downloading files with Bittorrent.’

‘He originally downloaded a file that was labelled as ‘Never Gonna Give You Up’ and now it is clear that it had been mislabelled.’

‘Boris often Rick-Rolls senior ministers on Fridays.’