The spam campaign is being used to spread a malicious.exe file, taking advantage of a vulnerability in WinRAR which was patched in January. Researchers with 360 Threat Intelligence Center on Monday said that the campaign is possibly the first malware delivered through mail to exploit WinRar vulnerability The flaw was fixed in January, but there s no guarantee that everyone has updated the tool. The malicious.exe file infects the system with malware when a victim opens the. archive, which in turn contains a malicious. executable file called CMSTray.
Source: https://threatpost.com/critical-winrar-flaw-found-actively-being-exploited/142204/