The technical details of the WannaCry ransomware are not exhausted. Now that researchers have had more time to analyze its behavior, it is possible to develop a solid idea of its final impact. Kaspersky's director of Global Research and Analysis, Costin Raiu, indicated through his Twitter account that a little over 98 percent of the computers compromised by WannaCry use some variant of Windows 7, while the rest was distributed between Windows Server 2008 R2 and Windows 10 x64.
The first campaign of WannaCry has ended, and we must emphasize first, because there is no doubt that we will see new attacks in the coming months. All their creators need to do is modify the code and exploit another Windows vulnerability. If there is one thing WannaCry made evident, it is the conflict in update policies that certain companies and institutions apply. The reasons to delay an update are many, but ransomware makes no exceptions. Even so, the latest data from Kaspersky helps us visualize on which systems WannaCry had the most success. Its favorite target was Windows 7
The chart that director Costin Raiu shared on his Twitter account clearly shows that more than 98 percent of infections occurred on a build of Windows 7, followed by the multiple flavors of Windows Server 2008 R2 (which, by the way, uses the same kernel as Windows 7), and minimal penetration on Windows 10 x64. The big question is: Where is Windows XP? Microsoft released an emergency patch for that operating system, but Raiu said infections were "insignificant". What happened? As the days passed, it was confirmed that the worm could not directly attack XP, although in theory it could affect it through other means.
Of course, this data is concentrated on the telemetry that Kaspersky obtains, but it is enough to establish a trend. Windows 7 support will extend until 2020. So why did it hit so many computers? First, the obvious: Windows 7 dominates between 46 and 48 percent of the market. Its footprint is large, so it is logical that WannaCry has more success there. And second, any user who has tried to deploy or maintain Windows 7 recently knows well that Windows Update on that operating system is a disaster. The update service can take hours to process data, devouring CPU cycles. When that happens, many users decide to disable it, despite the risk.
