在WCry之前，这个病毒就在利用这个相同的漏洞给宿主安装Adylkuzz挖矿软件，并且给宿主关掉漏洞端口以避免重复感染。客观上，这个病毒让宿主对WCry有了免疫。
也算是一种疫苗呢……
Symptoms of the attack include a loss of access to networked resources and system sluggishness. Kafeine said that some people who thought their systems were infected in the WannaCry outbreak were in fact hit by the Adylkuzz attack. The researcher went on to say this overlooked attack may have limited the spread of WannaCry by shutting down SMB networking to prevent the compromised machines from falling into the hands of competing botnets.
Source: Massive cryptocurrency botnet used leaked NSA exploits weeks before WCry | Ars Technica