Finding an alert in the middle of your javascript
- by Ariel Popovsky
I was debugging a script injection issue the other day using some sample code with an alert in it. The alert was popping out meaning the code got executed leaving open the possibility for a hacker to put there some nasty malicious code. I knew my alert was being executed but didn’t know how. So I tried something that worked perfectly for this problem, replaced the native alert function with my own one. All I had to do in Chrome was open the javascript console and type: alert = function(msg){ console.log(msg); console.trace(); }; The next time the malicious code was executed, instead of the regular alert I got something similar to this: alert("testing") testing console.trace() alert:2 (anonymous function):2 InjectedScript._evaluateOn:312 InjectedScript._evaluateAndWrap:294 InjectedScript.evaluate:288 undefined In my case I was able to see what was going on and find the offending function. This was tested on Firebug in Firefox and it works as.
