Infection: js:ScriptXE-inf [Trj]

When I log into my website/blog my antivirus software warns me about an Trojan Horse.
And when I deactive the plugin that are infected it shows a new warning with a new plugin.
I also deactivaded all the plugins and activaded them one at the time the plugins that showed a warning I deactiveded again.
And when I was done that were 5 plugings that were “infected”.
But then it began again with other plugins… Including “Akismet”, “My Quicktags” etc…
And the common thing was that it always is the .js file in the pluginfile