The image probably isn't loaded by that time. I mean, it's probably a couple milliseconds, if that, between when you assign that src and when you ask for the width and height.

Some older browsers knew a little about JavaScript but couldn’t handle image effects. This line checks to see if the JavaScript code can detect any images on the page.

The first image (before rollover) has been given the name button1.This code says that the chgImg function is called by both the onMouseover and onMouseout event handlers, both of which pass ...

The authors turned to polyglot images to add the JavaScript code that redirects to a page offering a fake reward. The malicious code is hidden in a BMP type of picture and it is heavily obfuscated.

Researchers have discovered a relatively new way to distribute malware that relies on reading malicious obfuscated JavaScript code stored in a PNG file’s metadata to trigger iFrame injections.

The image, which is displayed to the right of this text, looked unremarkable. Using some clever HTML5 programming under the hood, however, it delivered malicious code to unsuspecting Mac users.