A security vulnerability was discovered recently in WinRAR, affecting over 500 millions of users worldwide. Due to the flaw residing in UNACEV2.dll code base that WinRAR uses to extract files from archives packed with the ACE format, hackers can not only bypass the access control to gain high system privileges, but also implant malicious files into the system to infect and control users’ computers.

It is reported that the UNACEV2.dll code base has not been updated since 2005, and attackers can easily enter and implement code execution. WinRAR has been negatively affected by a variety of serious security vulnerabilities over the past 19 years. When a user opened a SFX file, an attacker could the vulnerability to remotely execute malicious code.

In order to give users a safer experience, WinRAR deleted the UNACEV2.dll file, and announced ACE archive format will no longer be supported. They has also fixed the vulnerability in the latest version 5.70 Beta 1.

360 Security Center has blocked such attacks, and reminded users of the risk. Uses can install 360 Total Security to block possible attacks and effectively protect computers from this security issue.