> PHP2Shell: Suspected North Korean campaign targets 216 vulnerable PHP hosts

Cyfirma links PHP2Shell scans of 216 vulnerable hosts to a suspected North Korean campaign using AI to rank public exploits. On October 21, PHP released emergency patches for two critical vulnerabilities, CVE-2026-109618 and CVE-2026-109619, both rated 9.2 on the CVSS scale. The flaws affect all PHP versions that handle web requests. The vulnerable code dates back to PHP 5.4, released in 2012, and resides in the PHP engine itself rather than in individual applications. Attackers can exploit the flaws to execute code remotely by sending specially crafted HTTP requests, without authentication. Exploitation attempts increased rapidly after the vulnerabilities became public. Cloudflare researchers reported tens of thousands of attempts within the first 45 minutes, hundreds of thousands in just two hours, and millions by October 22. Cyfirma reported that a group of North Korea-linked group has identified 216 hosts that may still be vulnerable to PHP2Shell. The operators communicate through a private I2P channel that Cyfirma has monitored since October 22. On October 24, they reported that 216 hosts appeared to be unpatched or only partly protected, earlier than Cyfirma expected. They are checking the systems from 21 compromised machines. At the time Cyfirma captured the conversation, the operators had already checked about one-third of the targets. “Two handles active since March 2026, coordinating in a closed I2P channel; staging infrastructure shared in-channel.” states the cybersecurity firm. “Target set and scan nodes. “On 24 October the operators reported 216 unpatched or partially mitigated hosts and named 21 scan nodes; the same addresses were seen performing web-shell tooling and upload-progress session-poisoning attempts.” The scanning is slow on purpose. Volume stays low, the machines rotate, and any node that shows filtering or rate limiting gets pulled and never reused. That’s why a rate-based alert will probably stay quiet. Who’s behind it? Cyfirma assesses with moderate confidence a link to the Lazarus family of North Korean groups, based on language, operating style and old habits with PHP web shells and hijacked web servers. It has no shared malware or infrastructure to point to yet, and it admits that a Korean-speaking criminal crew without state backing would fit the same facts. Its confidence in the campaign itself is high. Government agencies and banks come first. Next in line are logistics, ports, airports and aviation, manufacturing, and online transaction and trading platforms. The countries named are the US, Japan, South Korea, Thailand, Indonesia, Australia, Taiwan, India, Singapore, the UAE, Saudi Arabia and the EU. Cyfirma has not named any victims or seen the full list of targeted systems. The operators have not announced when they plan to launch attacks, and the researchers have not confirmed that this group has compromised systems on a large scale. Cyfirma gives the campaign an imminence score of 78 out of 100. The operators plan to check all 216 hosts, select the most promising targets, and decide which publicly available exploits to adapt. The group does not appear to be developing new exploits. Instead, its members use a local AI model to rank public exploit repositories, then test the results manually in a lab. Cyfirma believes this approach could help attackers turn newly disclosed vulnerabilities into working attacks more quickly. However, researchers warn that some proof-of-concept exploits shared online are fake and may contain malware, so downloading and running them can be dangerous. Technical details leaked on October 20, ahead of coordinated disclosure, and the PHP project shipped fixes on October 21. Apache mod_php with default settings and prefork is the confirmed worst case for 109618, with full unauthenticated code execution. For 109619, PHP-FPM is validated through the upload-progress path. One correction matters for your temporary controls. Early coverage tied the session upload-progress field to 109618, but PHP’s advisories put it under 109619 only. Disabling upload progress does nothing for 109618, so the two bugs need different stopgaps. Triggering the bug is easy, but reliable code execution isn’t. The attacker has to land a follow-up request on the same worker and shape heap data into the freed space, otherwise the worker crashes or answers normally. VulnCheck reports working code execution on x86-64 with ASLR enabled against PHP 8.4.10 to 8.4.26, while ARM64 only leaks memory so far. Short of code execution, attackers have already shown worker crashes, arbitrary file reads through OPcache and a leak of about 67 KB of process memory. The fixed releases are PHP 8.5.12, 8.4.27, 8.3.36 and 8.2.35. PHP 8.1, 8.0 and 7.4 get only minimal backports, and vendors such as cPanel EasyApache, CloudLinux, TuxCare and Plesk carry their own builds, so confirm coverage with yours. Anything from PHP 5.4 to 7.3 has no fix, so migrate or isolate it. Restart every worker after patching, because a reload that keeps old workers alive leaves the stale state in place. Isolate anything internet-facing that you can’t patch within hours, starting with Apache mod_php. If you suspect a host is compromised, capture memory and logs before you patch, since a restart destroys the CVE-2026-109619 state. Then rebuild the host from a trusted image and rotate every secret the PHP worker could reach. Hunt back to October 17, the earliest known exploitation, and use long time windows. The strongest single signal is a PHP or web server process spawning something it never normally spawns. Application logs will usually show nothing, because the bug fires before application code runs. Look for odd multipart POSTs to endpoints that never take uploads, bursts of worker crashes and memory errors, new PHP files in web roots, and new cron jobs, local users or SSH keys. Cyfirma includes Sigma, Splunk and YARA content, though it says the YARA set hasn’t been tested on real application code yet. It also lists 21 scan-node addresses, 17 source addresses from October 23 and 15 staging addresses, all defanged. Some scan nodes are described as compromised and may belong to victims, so hunt for prior contact before assuming who owns them. If you can’t patch yet, the advisory suggests limits such as a low post_max_size and disabling session upload progress for 109619. Cyfirma is clear that none of it replaces patching. The operators’ own selection rule is the most useful detail in the whole advisory, because they dropped every host that showed a fixed version or sat behind heavy filtering. That makes a current version string a cheap filter against you, and for once being boring pays off. “Hosts still bannering older PHP are the ones the operators kept.” Cyfirma states. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, PHP2Shell)