TeamPCP Compromises Checkmarx Jenkins AST Plugin Weeks After KICS Supply Chain Attack

TL;DR — TeamPCP has published a malicious version of the Checkmarx Jenkins AST plugin to the Jenkins Marketplace, marking the second major supply chain compromise of Checkmarx infrastructure in weeks. Users must upgrade to version 2.0.13-848.v76e89de8a_053 or later. The rapid re-compromise suggests either incomplete credential rotation or retained access from the earlier March 2026 KICS breach.

What happened

Checkmarx confirmed over the weekend that a modified version of its Jenkins AST plugin was published to the Jenkins Marketplace. The company advised users to ensure they are running version 2.0.13-829.vc72453fa_1c16, published on December 17, 2025, or earlier versions. A patched version, 2.0.13-848.v76e89de8a_053, has since been released to both GitHub and the Jenkins Marketplace, though Checkmarx's incident statement indicated it was still in the process of publishing the new version at the time of disclosure.

According to security researcher Adnan Khan and SOCRadar, TeamPCP gained unauthorized access to the plugin's GitHub repository and renamed it to "Checkmarx-Fully-Hacked-by-TeamPCP-and-Their-Customers-Should-Cancel-Now." The defaced repository description also included: "Checkmarx fails to rotate secrets again. with love – TeamPCP."

This incident follows a series of TeamPCP attacks against Checkmarx that began in March 2026. Weeks prior, the group compromised the KICS Docker image, two VS Code extensions, and a GitHub Actions workflow to distribute credential-stealing malware. That breach cascaded to a brief compromise of the Bitwarden CLI npm package, which served similar malware capable of harvesting developer secrets.

Checkmarx has not disclosed the mechanism by which the malicious plugin version was published to the Jenkins Marketplace.

Why it matters

Jenkins AST plugins are widely deployed in CI/CD pipelines across development teams. A compromised plugin distributed through the official Jenkins Marketplace poses a direct threat to any organization relying on the Checkmarx integration for security scanning and policy enforcement.

For SOC analysts and platform engineers in the MENA region, this incident demonstrates a critical pattern: attackers are not simply breaching infrastructure once and departing. TeamPCP's return to Checkmarx systems within weeks suggests either persistent access or systematic reconnaissance of remediation gaps. The reuse of similar attack infrastructure (credential stealers) across multiple Checkmarx products indicates a sustained, resource-intensive campaign targeting the software supply chain.

The compromise of developer tooling is particularly dangerous because it operates within the trust boundary of engineering teams—plugins and extensions are expected to be legitimate and are often given broad permissions over build systems and repositories.

Affected systems and CVEs

Checkmarx Jenkins AST plugin (malicious version distributed via Jenkins Marketplace)
Checkmarx KICS Docker image (prior compromise, March 2026)
Checkmarx VS Code extensions (prior compromise, March 2026)
Checkmarx GitHub Actions workflow (prior compromise, March 2026)
Bitwarden CLI npm package (collateral compromise from Checkmarx breach)

No CVE assigned at the time of publication.

What to do

Update Checkmarx Jenkins AST plugin immediately to version 2.0.13-848.v76e89de8a_053 or later on all Jenkins instances.
Rotate all credentials and secrets associated with Checkmarx infrastructure, GitHub accounts, and systems integrated with Checkmarx tooling.
Audit GitHub repository access logs and permissions for the Checkmarx Jenkins AST plugin repository and related projects.
Review deployment records to identify whether any malicious plugin versions were installed in your environment and when.
If you use Checkmarx KICS, VS Code extensions, or GitHub Actions workflows, verify you are running current versions and review their deployment history.
Inspect build logs and artifact repositories for any unusual activity correlating with plugin deployments.

Open questions

How did TeamPCP obtain credentials or access to publish the malicious plugin version to the Jenkins Marketplace, and what authentication controls were bypassed.
The full scope of data or systems accessed via the compromised plugin before discovery.
Whether the December 2025 re-compromise used the same initial access vector as the March 2026 KICS breach or exploited a different entry point.
The timeline between when the malicious plugin was published and when Checkmarx detected and removed it; this affects the window of exposure for downstream users.
Whether remediation efforts after the March 2026 incident included comprehensive credential rotation across all systems and third-party integrations.