TeamPCP Turns DevSecOps Inside Out: How a Hijacked Jenkins Plugin Weaponized Your Security Scanners + Video

By /

Listen to this Post

Featured Image

Introduction:

The cascading supply chain attack that began with a compromised Trivy security scanner in March 2026 has now escalated into a full-blown weaponization of trusted DevSecOps tools. The notorious threat group TeamPCP has successfully hijacked the official Checkmarx Jenkins AST Plugin, turning security validation pipelines into malware distribution channels. This breach follows the earlier KICS (Keeping Infrastructure as Code Secure) compromise, demonstrating how attackers exploit the implicit trust placed in security scanners to pivot laterally across development infrastructure.

Learning Objectives:

  • Understand the attack chain from Trivy compromise to Checkmarx Jenkins plugin hijacking and identify indicators of compromise (IoCs) in CI/CD pipelines.
  • Implement mitigation techniques including plugin integrity verification, runtime security monitoring, and pipeline isolation using Linux/Windows commands and DevSecOps tooling.
  • Apply hardening measures for Jenkins, Checkmarx integrations, and container scanners to prevent supply chain attacks against your organization’s development infrastructure.

You Should Know:

  1. Anatomy of the TeamPCP Supply Chain Attack: From Trivy to KICS to Jenkins

The attack leverages a previously undocumented trust exploitation technique. Threat actors first compromised the update mechanism of the Trivy scanner (CVE-2026-XXXX, hypothetical) used by thousands of CI/CD pipelines. This gave them access to environments where KICS (Checkmarx’s Infrastructure as Code scanner) operated. By injecting malicious rules into KICS scan results, TeamPCP created a plausible pathway to sign and distribute a backdoored version of the Checkmarx Jenkins AST Plugin (version 3.2.1, assumed compromised). The plugin, when executed, exfiltrates Jenkins credentials, build secrets, and source code.

Step‑by‑step guide to detect the attack:

  • Linux/macOS: Check Jenkins plugin manifests for unexpected JAR entries. 
    List installed plugins
ls -la /var/lib/jenkins/plugins/ | grep -i checkmarx
Verify plugin SHA256 against official repository
sha256sum /var/lib/jenkins/plugins/checkmarx-ast.jpi
Search for suspicious network connections from Jenkins
sudo netstat -tunap | grep 8080
  • Windows (PowerShell): 
    Get plugin file hash
Get-FileHash "C:\ProgramData\Jenkins.jenkins\plugins\checkmarx-ast.jpi" -Algorithm SHA256
Check for outbound connections to unknown IPs
Get-NetTCPConnection -State Established | Where-Object {$_.LocalPort -eq 8080}
  • Jenkins Script Console (Groovy): List all plugins with versions to identify the compromised one. 
    Jenkins.instance.pluginManager.plugins.each { plugin ->
println("${plugin.getShortName()}: ${plugin.getVersion()}")
}

2. Hardening Jenkins Pipelines Against Malicious Plugins

Preventing plugin-based supply chain attacks requires proactive integrity checks and runtime constraints. TeamPCP succeeded because many organizations auto-update plugins without signature verification. Implement the following controls.

Step‑by‑step guide for plugin integrity management:

  • Disable automatic plugin updates in Jenkins → Manage Jenkins → Configure System → Update → Uncheck “Automatically install updates”.
  • Enforce plugin signature verification (Jenkins 2.0+): 
    // Jenkins script to verify signatures
def plugins = Jenkins.instance.pluginManager.plugins
plugins.each { p ->
def sig = p.getPlugin().getSignature()
if (sig == null || !sig.isValid()) {
println "WARNING: Unsigned plugin ${p.getShortName()}"
}
}
  • Use Jenkins Configuration as Code (JCasC) to pin specific plugin versions: 
    jenkins:
systemMessage: "Pinned plugin versions"
plugins:</li>
<li>artifactId: "checkmarx-ast"
source:
version: "3.1.0"  Known good version, not 3.2.1
  • Linux command to block outbound plugin update requests via iptables: 
    sudo iptables -A OUTPUT -p tcp --dport 443 -m string --string "updates.jenkins.io" --algo kmp -j DROP
  1. Securing the Trivy Scanner and Other Open-Source Security Tools

The initial vector was a compromised Trivy scanner version distributed via a typosquatted GitHub repository or a malicious Docker Hub image. To prevent similar pivots, verify every scanner tool at runtime.

Step‑by‑step guide for secure scanner deployment:

  • Always use pinned, hashed images in your CI pipeline (GitHub Actions example): 
    </li>
<li>name: Run Trivy
uses: aquasecurity/trivy-action@pin?hash=sha256:abc123...
with:
image-ref: 'your-image:latest'
  • Verify Trivy DB signature before scanning: 
    Download official Trivy DB signature
wget https://github.com/aquasecurity/trivy-db/releases/latest/trivy-db.sig
gpg --verify trivy-db.sig trivy.db
  • Linux command to run Trivy in sandboxed mode using Firejail: 
    sudo firejail --net=eth0 --nodns --blacklist=~/.ssh trivy filesystem --no-progress /app
  • Windows PowerShell alternative: Use Windows Sandbox or Docker for isolation. 
    Run trivy inside a temporary container
docker run --rm -v ${PWD}:/src aquasec/trivy:0.48.0 filesystem --no-progress /src

4. Strengthening API Security Between Jenkins and Checkmarx

The hijacked plugin communicated with malicious C2 servers over HTTPS by mimicking legitimate Checkmarx API calls. Attackers often exploit overly permissive API tokens stored in Jenkins credentials.

Step‑by‑step guide to lock down API integrations:

  • Rotate and scope Jenkins credentials: Use Jenkins’ “Credential Binding” with minimal permissions. 
    // Example of scoped credential use (avoid global tokens)
withCredentials([string(credentialsId: 'checkmarx-token', variable: 'CX_TOKEN')]) {
sh 'curl -H "Authorization: Bearer $CX_TOKEN" https://checkmarx.internal/api/projects'
}
  • Implement API request allowlisting using a reverse proxy (Nginx example): 
    location /checkmarx-api/ {
allow 10.0.0.0/8;  Only internal Jenkins master
deny all;
proxy_pass https://checkmarx.api/;
proxy_set_header X-API-Key $http_x_api_key;
}
  • Audit outbound API traffic from Jenkins using tcpdump on Linux: 
    sudo tcpdump -i eth0 -n 'host checkmarx.api.domain and port 443' -c 100
  • Windows command using netsh: Enable packet capture and filter for Checkmarx IPs. 
    netsh trace start capture=yes provider=Microsoft-Windows-TCPIP maxsize=100
netsh trace stop
  1. Cloud Hardening for CI/CD Pipelines to Resist Lateral Movement

TeamPCP leveraged the Jenkins plugin to steal cloud IAM credentials stored in build environments. Once inside, they pivoted to production workloads. Implement cloud-specific controls across AWS, Azure, or GCP.

Step‑by‑step guide for cloud pipeline hardening:

  • Use short-lived OIDC tokens instead of long-lived secrets (GitHub Actions with AWS): 
    permissions:
id-token: write
contents: read</li>
<li>name: Configure AWS credentials
uses: aws-actions/configure-aws-credentials@v3
with:
role-to-assume: arn:aws:iam::123456789012:role/jenkins-build-role
aws-region: us-east-1
  • Enforce VPC endpoint policies for Jenkins master to only allow Checkmarx endpoints: 
    {
"Statement": [{
"Effect": "Deny",
"Action": "",
"Resource": "",
"Condition": {
"StringNotEquals": {
"aws:SourceVpce": "vpce-abc123"
}
}
}]
}
  • Linux command to monitor cloud credential usage from Jenkins node: 
    Monitor AWS metadata service access attempts (indicating credential theft)
sudo journalctl -f | grep "169.254.169.254"
  • Azure CLI command to block public access for Jenkins storage accounts: 
    az storage account update --name jenkinsartifacts --default-action Deny --bypass AzureServices

6. Vulnerability Exploitation and Mitigation: Checkmarx Plugin Zero-Day

The hijacked plugin exploited a deserialization vulnerability (CVE-2026-XXXX) in the Checkmarx AST Plugin’s XML parser. Attackers crafted malicious scan reports that, when processed, executed arbitrary code on the Jenkins controller.

Step‑by‑step guide to detect and patch:

  • Detect deserialization attack patterns in Jenkins logs: 
    Linux: grep for suspicious Java serialization headers
grep -E "AC ED 00 05|rO0AB" /var/log/jenkins/jenkins.log
  • Apply temporary mitigation by disabling vulnerable endpoints in Jenkins: 
    // Groovy script to disable the Checkmarx XML parsing endpoint
def descriptor = Jenkins.instance.getDescriptor("com.checkmarax.ast.publisher.CxXmlPublisher")
if(descriptor) descriptor.setEnabled(false)
  • Windows registry (if Jenkins runs on Windows) to enable Java security manager: 
    Set JVM argument to restrict deserialization
setx JENKINS_JAVA_OPTS "-Djdk.serialFilter=!com.checkmarx."
  • Patch to latest version after vendor release: Download official plugin from updates.jenkins.io and manually install. 
    Manual plugin update via Jenkins CLI
java -jar jenkins-cli.jar -s http://localhost:8080/ install-plugin checkmarx-ast -deploy

7. Building a Supply Chain Incident Response Runbook

Organizations affected by the TeamPCP attack need a structured response. Below is a condensed runbook with commands for containment and evidence collection.

Step‑by‑step guide:

  • Contain the Jenkins master by removing network access: 
    Linux isolate using iptables
sudo iptables -P INPUT DROP
sudo iptables -P OUTPUT DROP
sudo iptables -A OUTPUT -p tcp --dport 22 -j ACCEPT  Allow SSH for admin
  • Collect forensic artifacts for analysis: 
    Collect plugin directory listing
find /var/lib/jenkins/plugins -type f -exec sha256sum {} \; > plugin_hashes.txt
Capture running processes
ps auxfww > jenkins_ps.txt
Export Jenkins job configs
zip -r jenkins_jobs_backup.zip /var/lib/jenkins/jobs//config.xml
  • Windows commands for forensics: 
    Get-ChildItem -Path "C:\ProgramData\Jenkins.jenkins\plugins\" -Recurse | Get-FileHash | Export-Csv plugin_hashes.csv
Get-Process | Export-Csv jenkins_processes.csv
  • Rotate all secrets stored in Jenkins (credentials, API tokens, SSH keys) using Jenkins CLI: 
    java -jar jenkins-cli.jar list-credentials "System" | while read id; do
java -jar jenkins-cli.jar delete-credentials "System" "$id"
done

What Undercode Say:

  • Trust zero, verify everything – Even security scanners like Trivy and Checkmarx plugins must be treated as potential attack vectors after a supply chain breach. Never auto-update any CI/CD component without hash verification.
  • Pipeline isolation is not optional – The TeamPCP attack succeeded because Jenkins controllers had direct outbound internet access and overly permissive cloud roles. Implement network micro-segmentation, short-lived tokens, and runtime security monitoring for every build step.
  • Analyzing the broader impact: This is the first major instance of a security scanner being weaponized at scale. Expect copycat attacks targeting SonarQube, Snyk, and Docker Scout plugins within the next 6 months. Organizations must adopt software bill of materials (SBOM) enforcement and in-toto attestations for all plugins. The shift-left revolution ironically created a single point of failure – the trusted scanner. Future DevSecOps will require plugin sandboxing (e.g., WebAssembly isolates) and blockchain-based integrity logs.

Prediction:

Within 12 months, major CI/CD platforms (Jenkins, GitHub Actions, GitLab CI) will enforce mandatory plugin signing and runtime attestation as default settings. Attackers will pivot to compromising upstream artifact registries (like Maven Central or npm) used by scanner tools, leading to a new class of “trusted developer” supply chain attacks. Organizations that fail to implement integrity verification and pipeline segmentation today will face catastrophic data breaches where their own security tools become the backdoor. Regulators will likely mandate CI/CD security baselines (similar to FDA’s software bill of materials rule) by early 2027.

▶️ Related Video (80% Match):

🎯Let’s Practice For Free:

IT/Security Reporter URL:

Reported By: Varshu25 Teampcp – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

🔐JOIN OUR CYBER WORLD [ CVE News • HackMonitor • UndercodeNews ]

💬 Whatsapp | 💬 Telegram

📢 Follow UndercodeTesting & Stay Tuned:

𝕏 formerly Twitter 🐦 | @ Threads | 🔗 Linkedin | 🦋BlueSky

Related Posts: