4chan was hacked due to outdated PDF software and is back online

The online forum 4chan was unavailable for over ten days, but the service is now back online. The site went offline on April 14, 2024 after an extensive hacker attack. Because internal information and the source code had also been copied by unauthorized persons, some observers assumed that the infamous 4chan could disappear permanently from the internet.

However, as early as the middle of the week, an email published on X by one of the administrators, known as "Janitor" in 4chan jargon, indicated that repairs were being made. Janitor "GrapeApe" wrote that all passwords had been changed and two servers that had been in use since 2010 had been taken offline. The use of PDFs on the site had been switched off and the operating systems of the remaining servers were being updated.

In an unnamed blog post published the following weekend, but on the 4chan domain, the service detailed the reasons for the hack and the nature of the recovery. As of Sunday, April 27, 2025, this post is also pinned to the homepage of all 4chan sub-forums. According to the text, the intrusion into the systems only took place on April 14, 2025 by uploading a prepared PDF file. Shortly afterward, a competing forum reported that it had had access to 4chan's internal information for months. The attacked service now apparently contradicts this, although the statements of both sides should be viewed with the utmost caution.

Outdated hardware and software

According to 4chan, "too few qualified person-hours were available to update the code and infrastructure". In short, the hardware and software were outdated. The servers themselves have been gradually replaced over the past year, but not fast enough, the operators write. The upload of PDFs has been temporarily switched off and Flash files will no longer be offered permanently. There used to be a separate sub-forum for this, which has now been deleted. Adobe had already discontinued support for Flash at the end of 2020 and has since warned against using the format.

4chan has been notorious for its controversial content for years. Posts are made anonymously by default, copyrights are ignored and posts with right-wing extremist or anti-Semitic content are tolerated. Time and again, problematic trends on the internet have originated there, such as the influential conspiracy narrative surrounding "QAnon".

(nie)