WannaCry Ransomware: How EternalBlue Turned One Infection Into a Global Epidemic
On 12 May 2017, the WannaCry ransomware worm rapidly infected more than 230,000 computers across at least 150 countries by exploiting the unpatched SMBv1 vulnerability with the EternalBlue exploit. The malware combined remote code execution via EternalBlue with file encryption and ransom demands in Bitcoin, affecting hospitals, manufacturers, and government organizations worldwide. Microsoft had released the MS17-010 patch two months earlier, yet many systems remained vulnerable due to delayed deployment in large environments. WannaCry scanned both local subnets and random public IPv4 addresses in parallel threads, allowing infected machines to autonomously discover and compromise new targets without user interaction. Security researcher Marcus Hutchins halted the initial wave by registering a hardcoded kill-switch domain, though later variants removed this check. The incident demonstrated how a known, patchable flaw combined with worm-like propagation could produce worldwide operational disruption.
HabrOct 9, 2026Translated from Russian