Core Viewpoint - The article discusses the recent hacking incident involving the infamous online forum 4chan, detailing the methods used by the hacker to gain access and the subsequent impact on the platform [17][38]. Group 1: Overview of 4chan - 4chan is described as a highly controversial and unregulated forum with a monthly active user base of 20 million and peak concurrent users reaching 200,000 [6][7]. - The forum is known for its extreme and often offensive content, including a section dedicated to "politically incorrect" discussions [8][12]. - It has been a source of various internet memes and cultural phenomena, but also a platform for misinformation, with 12% of fake news on Reddit traced back to 4chan [10][12]. Group 2: Hacking Incident - On April 14, 4chan became inaccessible due to a hacking incident, which was later confirmed to be a result of a successful attack by a hacker who claimed responsibility on a rival forum [17][18]. - The hacker released 120 GB of sensitive data, including source code, moderator information, and user IP addresses, demonstrating the severity of the breach [20][21]. Group 3: Method of Attack - The hacker exploited a vulnerability by uploading a malicious file disguised as a PDF, which was actually a PostScript file, taking advantage of 4chan's lack of file validation [29][30]. - The attack was facilitated by an outdated version of Ghostscript used by 4chan, which allowed the hacker to execute commands and gain server access [35][36]. - Following the breach, 4chan has updated its security measures, including replacing affected servers and disabling the PDF upload feature temporarily [38][39]. Group 4: Implications and Reactions - The incident highlights a shift in hacking techniques, moving away from social engineering to exploiting technical vulnerabilities, which has surprised many in the cybersecurity community [41][42]. - After two weeks of downtime, 4chan resumed operations, continuing to attract attention for its controversial content [42].