4chan returns after major cyberattack

After suffering what it called a ‘catastrophic’ cyberattack earlier this month, controversial image board 4chan has returned online, admitting its systems were breached through outdated software.

The attacker, reportedly using a UK-based IP address, gained entry by uploading a malicious PDF, allowing access to 4chan’s database and administrative dashboard. The intruder exfiltrated source code and sensitive data before vandalising the site, which led to its temporary shutdown on 14 April.

Although 4chan avoided directly naming the software vulnerability, it indirectly confirmed suspicions that a severely outdated backend—possibly an old version of PHP—was at fault. The site confessed that slow progress in updating its infrastructure resulted from a chronic lack of funds and technical support.

It blamed years of financial instability on advertisers, payment processors, and providers pulling away under external pressure, leaving it dependent on second-hand hardware and a stretched, largely volunteer development team.

Despite purchasing new servers in mid-2024, the transition was slow and incomplete, meaning key services still ran on legacy equipment when the breach occurred. Following the attack, 4chan replaced the compromised server and implemented necessary software updates.

PDF uploads have been suspended, and the Flash board permanently closed due to the difficulty in preventing similar exploits through .swf files.

Now relying on volunteer tech workers to support its recovery efforts, the site insists it won’t be shut down. ‘4chan is back,’ it declared, claiming no other site could replace its unique community, despite long-standing criticism over its content and lax moderation.

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