Author Topic: Javascript browser keylogger  (Read 1238 times)

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Offline DukeSe

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Javascript browser keylogger
« on: June 17, 2014, 10:41:28 am »
I just wondered if anyone can take a look at this simple javascript code and tell me if could be used as a browser keylogger, by running the script on the target's browser without his/her consent! The problem is how the contents of  variable 'sen' could be recieved by the attacker?
Code: [Select]
<html>
<head>
<title>
notepad
</title>
<script>
sen="";
function display(eve) {
if (eve.keycode) key=eve.keycode;
else key=eve.which;
k=String.fromCharCode(key);
sen=sen+k;
}
</script>
</head>
<body onKeyPress="display(event)">
</body>
</html>
« Last Edit: June 17, 2014, 10:54:46 am by Kulverstukas »

Offline LsD

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Re: Javascript browser keylogger
« Reply #1 on: June 17, 2014, 07:28:30 pm »
Where is this logging the keystrokes?

This is obviously a troll thread. If not, then you're inconceivably autistic if you think you can even begin to do this.

Offline DukeSe

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Re: Javascript browser keylogger
« Reply #2 on: June 17, 2014, 09:03:07 pm »
If i am right 'Sen' variable stores the keystrokes!

Offline InfosecFurry

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Re: Javascript browser keylogger
« Reply #3 on: June 17, 2014, 09:15:27 pm »
Storing data in a variable is all fine and well, but it's not logging anything. Logging -> writing to persistent storage (on disk, shm, sqlite db in RAM, sending it over a network, etc)

Also, this will only log what is being typed within the context of a browser window and has no bearing on what users type in other applications.
There are no pentesters in fox-holes

Offline DukeSe

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Re: Javascript browser keylogger
« Reply #4 on: June 17, 2014, 09:59:53 pm »
Thnx fr that man, I misundrstd that code!

Offline m0l0ko

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Re: Javascript browser keylogger
« Reply #5 on: July 05, 2014, 09:00:50 pm »
Storing data in a variable is all fine and well, but it's not logging anything. Logging -> writing to persistent storage (on disk, shm, sqlite db in RAM, sending it over a network, etc)

Also, this will only log what is being typed within the context of a browser window and has no bearing on what users type in other applications.


Context of a browser window if run in an iframe, context of the browser if installed as a user script. As for storing data, I can think of a way to do that but I don't wanna be arming script kiddies with knowledge that will help them invade peoples privacy (not saying the OP is, but skiddies may come across the thread) so I'll just say this: AJAX same-domain-policy only prohibits receiving data. Doesn't block the request itself.
« Last Edit: July 05, 2014, 09:45:32 pm by m0l0ko »