Your website appears to contain malware. Malware is malicious software that may attempt to install dangerous software on visitor's computers to steal or delete personal information. The URL from alert details was marked as malware on at least one malware database.
If your site has been infected with malware, you need to take it offline and identify the malware source. Once you've identified the source of the problem, you should clean up your site and take action to prevent reinfection. Consult Web references for more information.