The WannaCry ransomware attacks that started on May 12, 2017 were blocked quickly when a kill switch was identified and activated, but how much money did WannaCry make during the time it was active?

WannaCry was a devastating global cyberattack, the likes of which had been predicted by many cybersecurity professionals but had yet to materialize. WannaCry was the fastest spreading ransomware ever created.

WannaCry combined ransomware with a worm, which allowed it to automatically spread and infect huge numbers of devices on a network. The ransomware exploited a vulnerability in Windows Server Message Block (SMBv1) using an NSA exploit called EternalBlue.

The flaw exploited by EternalBlue had been reported to Microsoft and a patch was issued in March 2017, two months before the attacks started. However, many businesses were slow to apply the patch and were vulnerable to attack. Within a matter of hours, around 200,000 computers had been attacked in 150 countries. It is worth noting here that there are still many computers that have not been patched more than 2 and a half years after the patch was released, in spite of widespread news coverage about the threat of attack and its huge cost. WannaCry is still one of the biggest ransomware threats and accounts for a significant percentage of all successful ransomware attacks in 2019.

WannaCry was blocked by a British security researcher who discovered the ransomware checked a domain name prior to encrypting data, but that domain name had not been registered. He purchased the domain name, thus preventing file encryption.

That said, the speed at which the ransomware spread meant many devices were infected and encrypted. Since businesses were not protected if the ransomware encryption had already started by the time the kill switch was activated, the attackers must have had a huge payday. So how much did WannaCry make?

By today’s standards, the ransom demand was very small. Just $300 per infected device, which doubled to $600 if the payment was not paid within 3 days. It is actually easy to see how many payments were made, as the transactions are detailed in the blockchain. The recipient remains anonymous, but the payments can be seen.

The three Bitcoin addresses known to have been used in the WannaCry attacks currently show 430 payments have been made and 54.43228033 BTC has been sent to those accounts. The value of BTC is somewhat volatile and was much higher at points between now and the attacks, but at today’s exchange rate that equates to around $386,905. Most of the BTC payments have now been moved out of the accounts so they attackers have managed to cash out. Payments are also still being made to those accounts. The latest payments to one of the addresses were made in December 2019.

$386,905 may not seem like much of a payday considering the number of devices infected and the damage caused by the attack, and it’s not. Further the attackers will need to convert that total to real money, and a considerable amount will be lost in that process. The payday was tiny considering the scale of the attack. However the cost of the attack to businesses was colossal.

The National Health Service in the United Kingdom was hit bad and the cleanup operation, and loss of business while that occurred, has been estimated to have cost £92 million. That was just one victim, albeit a major one. Estimates on the total cost of WannaCry range from hundreds of millions to $4 billion globally.

Next time you delay applying a patch or updating software, consider WannaCry and the potential costs of exploitation of a vulnerability. In all of the above cases – all 200,000+ attacks – applying the patch would have prevented the attack and the huge cost of remediation.