A new dangerous remote code execution vulnerability has been discovered in WinRAR software, affecting hundreds of millions of users worldwide. The flaw resides in the way an old third-party library, called UNACEV2.DLL, used by the software handled the extraction of files compressed in ACE data compression archive file format. Attackers can extract compressed files to a folder of their choice rather than the folder chosen by the user, leaving an opportunity to drop malicious code into Windows Startup folder where it would automatically run on the next reboot.
Source: https://thehackernews.com/2019/02/winrar-malware-exploit.html