javainstaller.jar ... is infected with Download.Adware

According to Symantec Security Check

Is this actually a threat? Should I delete it? Do I need to do anything else about it?

The computer seems to be working properly; I wasn't aware of any problems. I ran the security check just out of curiosity.

Is it really malware, or is it a legitimate part of Sun's jdk (or jre) installer?

 

Thanks for your reply chas. Actually, before you responded I had already uninstalled my jre and jdk, manually deleted the Application Data/sun directory, and installed the new versions of both jre and jdk (it was about time for me to do that already anyway), and now Symantec shows everything is clean.

But thanks also for pointing out that Java Control Panel. Actually there is no "cache" tab; I guess you meant the General/Temporary Internet Files section which has "Delete Files" and "Settings", and opens up a panel to set the cache parameters and also view info about what's in the cache. Good to know.