WannaCry Ransomware Attack (2017): The Day the World Stopped Clicking

On a sunny Friday morning in May 2017, employees at the UK’s National Health Service (NHS) came into work as usual, logging into their computers, ready to tackle the day’s responsibilities. But things took a turn for the worse. What started as routine quickly spiraled into a nightmare, as computer screens began flashing ransom notes instead of spreadsheets and patient records.

This was no ordinary crash—it was the infamous WannaCry ransomware attack, which left IT teams across the globe scrambling in panic.

What Is Ransomware?

Before we dive into the specifics of WannaCry, let’s back up a bit. Ransomware is a type of malware that locks you out of your own files and demands a ransom to regain access. In most cases, victims are asked to pay in cryptocurrency—usually Bitcoin—so that the attackers remain anonymous. It's the digital equivalent of locking up all your valuables in a vault and refusing to hand over the key unless you cough up the cash.

WannaCry, though, was on another level. It didn’t just hit random individuals but spread like wildfire across organizations, locking thousands of computers in over 150 countries. And its ripple effects were far more severe than most could have imagined.

The Zero-Day Exploit and NSA’s Role

Here’s where it gets juicy. The spread of WannaCry was made possible by a vulnerability in Microsoft’s Windows operating system, known as EternalBlue.

This wasn’t your average bug—it was a zero-day exploit discovered by the NSA (National Security Agency) in the U.S. The agency had identified this flaw and created a hacking tool that exploited it, presumably to use in cyber espionage operations.

However, that tool didn’t stay within their hands. It was leaked by a shadowy hacker group called the Shadow Brokers, who released EternalBlue into the wild.

It didn’t take long for cybercriminals to pounce. Within weeks, WannaCry was using this very exploit to propagate across vulnerable systems worldwide, effectively turning one government’s secret tool into a global disaster.

The Impact: Who Was Hit?

The WannaCry attack primarily affected organizations running older, unpatched versions of Windows. The National Health Service (NHS) in the UK was among the hardest hit, causing chaos in hospitals. Medical procedures were canceled, patient records became inaccessible, and even ambulances were diverted as the ransomware crippled essential healthcare infrastructure.

But it didn’t stop there. Other large organizations like FedEx, Telefonica, and even Renault were caught in the crossfire, suffering significant operational disruptions.

In all, it is estimated that the attack infected over 230,000 computers. The ransom demanded was small in comparison to the damage caused—about $300 per infected system, payable in Bitcoin. However, paying up wasn’t a guaranteed fix. In fact, many who did pay never regained access to their files.

Microsoft’s Response and the Race Against Time

To their credit, Microsoft acted quickly once the vulnerability was weaponized. They released a patch for the EternalBlue exploit in March 2017, well before the WannaCry attack. However, many organizations had failed to update their systems, either due to neglect or because they were still using outdated, unsupported versions of Windows.

After the attack started, Microsoft took the unprecedented step of releasing patches even for long-out-of-service versions of Windows, such as Windows XP. This was a critical move since many of the most vulnerable systems—like those used in hospitals—were running on ancient software.

Despite this, for many, the damage had already been done.

Who Was Behind It?

Here’s where the story gets a little murky. The Lazarus Group, a cybercrime syndicate believed to be linked to North Korea, is widely suspected to be behind WannaCry. While concrete evidence tying them directly to the attack remains elusive, similarities between the code used in WannaCry and other Lazarus Group operations have led many experts to point fingers in that direction.

The potential involvement of a nation-state adds a geopolitical dimension to the attack, suggesting that WannaCry wasn’t just a random crime, but possibly part of a larger, more sinister strategy of cyber warfare.