Math.random() javascript function *undefined* on Chrome

In first place, I am convinced that this is a trivial question, but I cannot understand why this is happening and I couldn't find an answer anywhere else. I googled my issue with little success, but if I missed something and just wasted your time please point me in the right direction and accept my humble excuses.

That said, here is what happens. I am building a simple script to display a graph drawn by a distributed algorithm (giraph) and I am working on Linux. I import all the libraries and, in particular, jQuery and everything works in Firefox (version 36.0.1). Switching to Chrome (version 41.0.2272.89 (64-bit)), the page stops working. Investigating the issue, I found out that the error was inside the jQuery.extend() function into the jQuery library, at the following line:

expando: "jQuery" + ( version + Math.random() ).replace( /\D/g, "" ),

In fact, trying to invoke Math.random() into the browser console leads to:

> Math.random();
> Uncaught TypeError: Undefined is not a function

Anyway, while typing the console autocompletes the "Math" variable, with the following result:

> Math
> function (){return "";}

This does not happen with Chrome on MacOS X Mavericks. Did anybody experience this kind of behaviour before?

EDIT: Unfortunately, I don't think that this is a namespace conflict. In my library I import only one other library (other than jQuery), which is Sigma js. As suggested, I wrote Math in the console and tried to understand which library did override Math (using "Show Function Definition"), with the following result, taken from a file named "VM53" (which I did not write and/or linked directly).

(function (){
    for (var i in window)
    {
    try {
            var jsType = typeof window[i];
            switch (jsType.toUpperCase())
            {                   
                case "FUNCTION": 
                    if (window[i] !== window.location)
                    {
                        if (window[i] === window.open || (window.showModelessDialog && window[i] === window.showModelessDialog))
                            window[i] = function(){return true;};
                        else if (window[i] === window.onbeforeunload)   // To try to fix onbeforeunload pop ups some users report seeing but I can't replicate.
                            window.onbeforeunload = null;
                        else if (window[i] === window.onunload)
                            window.onunload = null;                             
                        else
                            window[i] = function(){return "";};
                    }
                    break;                          
            }           
        }
        catch(err)
        {}      
    }

    for (var i in document)
    {
        try {
            var jsType = typeof document[i];
            switch (jsType.toUpperCase())
            {                   
                case "FUNCTION":
                    document[i] = function(){return "";};
                    break;                  
            }           
        }
        catch(err)
        {}      
    }

    try {
        eval = function(){return "";};              
        unescape = function(){return "";};
        String = function(){return "";};
        parseInt = function(){return "";};
        parseFloat = function(){return "";};
        Number = function(){return "";};
        isNaN = function(){return "";};
        isFinite = function(){return "";};
        escape = function(){return "";};
        encodeURIComponent = function(){return "";};
        encodeURI = function(){return "";};
        decodeURIComponent = function(){return "";};
        decodeURI = function(){return "";};
        Array = function(){return "";};
        Boolean = function(){return "";};
        Date = function(){return "";};
        Math = function(){return "";};
        Number = function(){return "";};
        RegExp = function(){return "";};

        var oNav = navigator;
        navigator = function(){return "";};
        oNav = null;            
    }
    catch(err)
    {}

})();