JS.Exception.Exploit is a detection for an exploit that allows Java applets to perform various actions on your system if you are using an older or unpatched version of Microsoft Internet Explorer.
In many cases, JS.Exception.Exploit may perform simple actions such as changing your Internet Explorer home page. (This is one of the most common uses of this exploit.) It has been reported, but not confirmed, that some adware programs use JS.Exception.Exploit to do this. As a result, your Symantec antivirus program may detect JS.Exception.Exploit when the adware program displays a pop-up ad that uses the exploit.
In many cases, JS.Exception.Exploit may perform simple actions such as changing your Internet Explorer home page. (This is one of the most common uses of this exploit.) It has been reported, but not confirmed, that some adware programs use JS.Exception.Exploit to do this. As a result, your Symantec antivirus program may detect JS.Exception.Exploit when the adware program displays a pop-up ad that uses the exploit.