Pretty much everyone is aware of how cool the Zip format actually is. It is pretty useful in compressing large files so that it would be easier to send them as attachments.
I used to use it heavily for sending multiple files is it into a single file, it made more sense since email providers did not allow multiple attachments, there was a limit on it.
I haven’t used them in a while, I know a lot of people who still use zip.
For example, there are many app developers who put together their app in a Zip file And upload in the cloud so that others can download unzip and then use their apps.
In fact, I just downloaded zip file which contains and uninstaller app for Mac.
Anyway, back to the topic of this article, the helpfulness of the zip format can be used as a means to harm your computer.
You may have come across the term called Zip Bomb.
It is a small zip file that contains multiple layers of knitted zip archives, the user has to unzip it and once it gets unzipped, it can render even the fastest machines unresponsive unavailable.
Developer named David Fifield has developed one of the most dangerous zip bomb ever.
It expands a tiny zip file, which is 46 MB in size, into a 4.5 terabyte of data.
Most of us have storage on our computers in TBs. Which means, 4.5 terabyte of data would require 4500 PCs if they all have one terabyte of storage on there PCs.
Give you a perspective, is standard movie file is 700 MB in size, which means 4.5 terabyte would 64285 movies worth of data.
And that’s all in a tine 46 MB zip file.
How was the Zip Bomb created?
“It works by overlapping files inside the zip container, in order to reference a ‘kernel’ of highly compressed data in multiple files, without making multiple copies of it.
The zip bomb’s output size grows quadratically in the input size; i.e., the compression ratio gets better as the bomb gets bigger,” writes Fifield in his blog.
In plain english, the zip archive has a limitation of how much it can compress, Fifield has some how removed that restriction so that his file can achieve compression rates that are far greater than the traditional archive. Hence a smaller file can expanded to a larger one.
Ideally, no readable data can be compressed to such extent and then expanded again to its working form, but since it’s a Zip Bomb, the purpose here is to slow down your PC.
How can you keep yourself safe from zip bombs?
Well if you have been following our blog? You always advise our readers to only download content from the trusted sources.
So if you do not download zip files from anywhere on the internet you are safe.
Keeping this in practice will not only save you from is it bombs but other malicious files as well that can do much more harm than as it Bob can