WannaCryptor

WannaCry, also known as WannaCryptor, WCry, WanaCrypt0r 2.0, and Wana Decryptor, is a Windows ransomware family that caused a global outbreak in May 2017. It encrypts victim files and presents a ransom demand, while also incorporating worm-like propagation that enabled rapid self-spreading across networks. The outbreak disrupted organizations worldwide, including critical healthcare environments in the United Kingdom.

The malware is widely associated with the North Korea-aligned Lazarus Group. Public attribution has linked WannaCry to Lazarus through code overlaps and shared development artifacts with earlier Lazarus malware. Reporting also identifies pre-outbreak variants and beta builds from early 2017, indicating development and testing before the large-scale campaign.

A defining characteristic of WannaCry was its use of the EternalBlue SMB exploit to spread between vulnerable Windows systems, allowing mass propagation where systems had not been patched. Separate reporting also notes an earlier near-identical variant that spread via SMB brute-forcing shortly before the main outbreak. This combination of ransomware functionality with automated network propagation made WannaCry unusually disruptive compared with conventional manually deployed ransomware.

WannaCry targeted Windows systems and is best classified as ransomware with worm-like behavior. Its known capabilities include encrypting data for extortion, propagating laterally through vulnerable hosts, and establishing broad post-compromise impact through automated spread. The malware remains one of the most consequential ransomware incidents due to its scale, speed of propagation, and operational linkage to Lazarus.