#USE GIFSICLE MALICIOUS IMAGE FULL#
#USE GIFSICLE MALICIOUS IMAGE CODE#

If a malicious code scanner doesn’t check the Exif data of image files then the malicious code could unnoticed in that as well. The code looks rather harmless by itself, so it could easily be missed when checking for malicious code. The first line reads the Exif data and the second executes the code stored in the image. In this case the file consisted of two lines of code: On its own the image file is harmless since the web server will not run the code stored in the Exif data, so a second file is used in conjunction with the image file. That code would evaluate (run) the data sent with POST variable zz1.

#USE GIFSICLE MALICIOUS IMAGE FULL#

When deobfuscated the full code in the model tag reads: Once one of the hackers had gained access to the website they placed malicious code into the Exif data, which stores information on the camera that took the photo, of existing images on the website. The hacker replaced the existing data on the camera maker and model with malicious code: The website in question had been repeatedley hacked through the exploitation of a vulnerability in an outdated version of the Joomla extensions JCE. While cleaning a website recently we dealt malicious code that was one hand better hidden to some detection methods, but on the other hand caused the fact the website was hacked to be identified when it hadn’t been otherwise identified for some time. Oftentimes they obfuscate the code in some way, though this often makes it easier to spot the malicious code since very little legitimate code on a website would be similarly obfuscated. Hackers use various methods to try to hide the malicious code they add to websites. Also, as with any media meant to convey meaning on the web, please make sure you’re including relevant alternative text.We don’t write much on what hackers do with websites once they hacked them since the focus of security companies should be on making sure that website don’t get hacked in the first place, which wouldn’t be hard to do if the companies were interested in that, but sometimes hackers are doing something worth discussing. A page full of gifs can make even a beefy computer or device strain itself, so just because you can bombard your users with animations doesn’t mean that you should (at least, if you care about user experience).

The smaller you go, the harder Gifsicle has to work to round everything out in fact, you may find that gifs with smaller dimensions sometimes carry a larger filesize.įinally, I’ll remind you that while gifs can be a lot of fun, they’re not always the best way to convey a message. 500×280 instead of 500×281) tend to resize much cleaner and with less distortion. In my testing, I’ve found that gifs with even dimensions (e.g. You may also notice that there was some rounding going on, even in my examples. You may have noticed there’s a bit of math involved with resizing images it’s nothing that requires an advanced degree, but it’s still not how I’d like to spend my afternoon. Even if you’re not using WordPress, I’d encourage you to look at the image_resize_dimensions() function and how it’s implemented this is a geometry problem that’s been solved before, so there’s no need to reinvent the wheel. Now that we have the hard-coded version, we’ll break this up into placeholders ( using proper escaping for shell arguments, of course) and we’ll find ourselves with the full, variable-filled version we had before! Gotchas With these numbers at hand, we can ask Gifsicle to resize our image to 267×150: Given the height, we can calculate the width thusly: $src_width / $src_height * $dst_height, or 500 / 281 * 150, which gives us a width of 267px.

Confused? Just remember that we have a 16:9 aspect ratio, meaning the height is the smaller dimension and thus cannot end up smaller than 150px or we risk our 150×150 frame not being filled. Now, let’s say we want a square version of that same image, at 150×150. In order to achieve this, we need to perform two operations: resizing the image to fit as much of it as possible into a 150×150 box, then crop off anything outside that area.įortunately, resizing the image is easy: Gifsicle has a -resize option, and the math that led us to our getimagesize()-compatible calculations up above would tell us that to fit a 500×281 image in a 150×150 box, our target dimensions would be 267×150. The original dimensions of this image are 500×281, approximately a 16:9 aspect ratio. Well, that was easy, wasn’t it? In case you’re not well-versed in juggling arguments and using PHP to assemble CLI commands, we’ll apply some real numbers: let’s say we have this gif of America’s Sweetheart, Nick Offerman:

Use gifsicle malicious image