Expect to see quite a few websites serving error pages today: Nearly 70 percent of websites need to update their core software to fix a pair of vulnerabilities that allow an attacker to seize full control over affected servers. Experts say there are working exploits for the flaws, and that these critical bugs are already being exploited in the wild.

Image: Shutterstock.com, Sashkin.

The flaws at issue are present in PHP, the programming language that powers sites running on a large number of web publishing systems, including Drupal, Magento, Joomla and WordPress. Earlier today, PHP released an emergency security update to fix two critical bugs that can allow an attacker to execute code of their choosing on a vulnerable server.

Reuters reports that government websites in Europe and elsewhere went offline today after the PHP vulnerabilities were disclosed. Cloudflare said it has already detected some exploitation of the flaw, and that at 3:02 am (UTC) it implemented web application firewall rules to protect websites from attack traffic seeking to exploit the bugs, which could cause a denial of service condition, remote code execution, and data exposure.

OpenAI, which was involved in the vulnerability research and outreach, said “given the severity of these flaws and PHP’s widespread use, we consider this one of the most impactful security issues in recent memory.”

Censys, a company that tracks the technology used by Internet hosts, said a recent scan identified approximately 2.58 million Internet facing hosts and 54.9 million web properties running PHP.

Security experts at Wiz said every PHP version released in the last decade is affected by at least one of these vulnerabilities [full disclosure: Wiz is an advertiser on this blog].

“These findings rank among the most severe vulnerabilities discovered in PHP, and arguably in software history,” reads a blog post published today by a team of researchers at Wiz, which was one of several organizations credited with discovering the vulnerabilities. “The underlying flaws had been present for decades, but demonstrating their exploitability required an exceptionally complex chain of steps, at the edge of what human researchers could practically achieve. Frontier AI models substantially reduced that barrier, turning a longstanding flaw into an exploit.”

The Wiz researchers say it is likely the PHP vulnerabilities will be mass-exploited to install web-based backdoors or “web shells,” which give attackers a web-based panel that allows them to remotely control infected sites. Wiz said that prior to the PHP bugs being publicly disclosed, the company worked with the PHP team, Calif and OpenAI to measure the size of the problem and coordinate patch verification and disclosure.

The PHP zero-day vulnerabilities are being tracked by their CVE numbers, CVE-2026-109618 and CVE-2026-109619, and they affect all web servers running PHP 5.4 or later. The bugs are fixed in PHP 8.5.12, 8.4.27, 8.3.36, and 8.2.35.

According to Wiz, PHP is so deeply embedded in many web applications that we are likely to see organizations struggling to patch these vulnerabilities for some time to come, comparing this PHP vulnerability pair with the Log4Shell weakness that emerged in 2021 — a widespread, severe-as-it-gets security flaw in Log4j, a popular Java logging framework.

“A vulnerability in core PHP reaches far beyond a single application,” the Wiz researchers wrote. “PHP runs across clouds, hosting providers, content-delivery networks and millions of independently managed servers. Reducing exposure before the technical details became public required coordinated work across that entire ecosystem.”

The SANS Internet Storm Center is keeping an eye on major software platforms that are shipping updates to deal with these PHP flaws. For example, Ubuntu just released updated PHP packages. For a technical deep-dive on these vulnerabilities that tells the timeline of the discovery of these bugs in a comic book style, check out this post from Calif, another technology company credited with finding the PHP flaws.

This is a fast-moving story. Updates will be noted here with timestamps.

Update, 2:30 pm ET: Add figures from Censys and a link to Calif’s writeup.

A financially motivated data theft and extortion group is attempting to inject itself into the Iran war, unleashing a worm that spreads through poorly secured cloud services and wipes data on infected systems that use Iran’s time zone or have Farsi set as the default language.

Experts say the wiper campaign against Iran materialized this past weekend and came from a relatively new cybercrime group known as TeamPCP. In December 2025, the group began compromising corporate cloud environments using a self-propagating worm that went after exposed Docker APIs, Kubernetes clusters, Redis servers, and the React2Shell vulnerability. TeamPCP then attempted to move laterally through victim networks, siphoning authentication credentials and extorting victims over Telegram.

A snippet of the malicious CanisterWorm that seeks out and destroys data on systems that match Iran’s timezone or have Farsi as the default language. Image: Aikido.dev.

In a profile of TeamPCP published in January, the security firm Flare said the group weaponizes exposed control planes rather than exploiting endpoints, predominantly targeting cloud infrastructure over end-user devices, with Azure (61%) and AWS (36%) accounting for 97% of compromised servers.

“TeamPCP’s strength does not come from novel exploits or original malware, but from the large-scale automation and integration of well-known attack techniques,” Flare’s Assaf Morag wrote. “The group industrializes existing vulnerabilities, misconfigurations, and recycled tooling into a cloud-native exploitation platform that turns exposed infrastructure into a self-propagating criminal ecosystem.”

On March 19, TeamPCP executed a supply chain attack against the vulnerability scanner Trivy from Aqua Security, injecting credential-stealing malware into official releases on GitHub actions. Aqua Security said it has since removed the harmful files, but the security firm Wiz notes the attackers were able to publish malicious versions that snarfed SSH keys, cloud credentials, Kubernetes tokens and cryptocurrency wallets from users.

Over the weekend, the same technical infrastructure TeamPCP used in the Trivy attack was leveraged to deploy a new malicious payload which executes a wiper attack if the user’s timezone and locale are determined to correspond to Iran, said Charlie Eriksen, a security researcher at Aikido. In a blog post published on Sunday, Eriksen said if the wiper component detects that the victim is in Iran and has access to a Kubernetes cluster, it will destroy data on every node in that cluster.

“If it doesn’t it will just wipe the local machine,” Eriksen told KrebsOnSecurity.

Image: Aikido.dev.

Aikido refers to TeamPCP’s infrastructure as “CanisterWorm” because the group orchestrates their campaigns using an Internet Computer Protocol (ICP) canister — a system of tamperproof, blockchain-based “smart contracts” that combine both code and data. ICP canisters can serve Web content directly to visitors, and their distributed architecture makes them resistant to takedown attempts. These canisters will remain reachable so long as their operators continue to pay virtual currency fees to keep them online.

Eriksen said the people behind TeamPCP are bragging about their exploits in a group on Telegram and claim to have used the worm to steal vast amounts of sensitive data from major companies, including a large multinational pharmaceutical firm.

“When they compromised Aqua a second time, they took a lot of GitHub accounts and started spamming these with junk messages,” Eriksen said. “It was almost like they were just showing off how much access they had. Clearly, they have an entire stash of these credentials, and what we’ve seen so far is probably a small sample of what they have.”

Security experts say the spammed GitHub messages could be a way for TeamPCP to ensure that any code packages tainted with their malware will remain prominent in GitHub searches. In a newsletter published today titled GitHub is Starting to Have a Real Malware Problem, Risky Business reporter Catalin Cimpanu writes that attackers often are seen pushing meaningless commits to their repos or using online services that sell GitHub stars and “likes” to keep malicious packages at the top of the GitHub search page.

This weekend’s outbreak is the second major supply chain attack involving Trivy in as many months. At the end of February, Trivy was hit as part of an automated threat called HackerBot-Claw, which mass exploited misconfigured workflows in GitHub Actions to steal authentication tokens.

Eriksen said it appears TeamPCP used access gained in the first attack on Aqua Security to perpetrate this weekend’s mischief. But he said there is no reliable way to tell whether TeamPCP’s wiper actually succeeded in trashing any data from victim systems, and that the malicious payload was only active for a short time over the weekend.

“They’ve been taking [the malicious code] up and down, rapidly changing it adding new features,” Eriksen said, noting that when the malicious canister wasn’t serving up malware downloads it was pointing visitors to a Rick Roll video on YouTube.

“It’s a little all over the place, and there’s a chance this whole Iran thing is just their way of getting attention,” Eriksen said. “I feel like these people are really playing this Chaotic Evil role here.”

Cimpanu observed that supply chain attacks have increased in frequency of late as threat actors begin to grasp just how efficient they can be, and his post documents an alarming number of these incidents since 2024.

“While security firms appear to be doing a good job spotting this, we’re also gonna need GitHub’s security team to step up,” Cimpanu wrote. “Unfortunately, on a platform designed to copy (fork) a project and create new versions of it (clones), spotting malicious additions to clones of legitimate repos might be quite the engineering problem to fix.”

Update, 2:40 p.m. ET: Wiz is reporting that TeamPCP also pushed credential stealing malware to the KICS vulnerability scanner from Checkmarx, and that the scanner’s GitHub Action was compromised between 12:58 and 16:50 UTC today (March 23rd).