Detect Aquasecurity Trivy Embedded Malicious Code (CVE-2026-33634) in Splunk
CVE-2026-33634 describes an embedded malicious code vulnerability (CWE-506) in Aquasecurity Trivy, a widely-used open-source vulnerability scanner. A compromised or trojanized Trivy binary may execute attacker-controlled code during container image scanning, CI/CD pipeline runs, or Kubernetes admission checks. Because Trivy is frequently granted elevated permissions to access container registries, Kubernetes API servers, and cloud credential chains, a backdoored instance poses critical supply-chain risk: exfiltration of secrets, lateral movement into CI/CD infrastructure, and persistent implant installation. This detection monitors for anomalous process behavior, unexpected network egress, and suspicious file activity originating from Trivy processes.
MITRE ATT&CK
SPL Detection Query
index=endpoint sourcetype IN ("XmlWinEventLog:Microsoft-Windows-Sysmon/Operational", "linux:syslog", "crowdstrike:events:sensor")
(process_name IN ("trivy", "trivy-linux-amd64", "trivy-linux-arm64") OR parent_process_name IN ("trivy", "trivy-linux-amd64", "trivy-linux-arm64"))
| eval suspicious_child=if(parent_process_name IN ("trivy","trivy-linux-amd64","trivy-linux-arm64") AND process_name IN ("curl","wget","nc","ncat","python","python3","perl","ruby","bash","sh") AND (match(process_cmd_line, "(?i)(/dev/tcp|base64|exec|reverse|shell|implant)") OR match(process_cmd_line, "(?i)(wget|curl).*(http)")), "true", "false")
| eval suspicious_network=if(process_name IN ("trivy","trivy-linux-amd64","trivy-linux-arm64") AND NOT (dest_port IN (443, 80) AND (match(dest_host, "aquasecurity") OR match(dest_host, "ghcr\.io") OR match(dest_host, "github\.com"))), "true", "false")
| eval suspicious_file=if(process_name IN ("trivy","trivy-linux-amd64","trivy-linux-arm64") AND match(file_path, "(?i)(/tmp/|/var/tmp/|/dev/shm/|C:\\\\Windows\\\\Temp)"), "true", "false")
| where suspicious_child="true" OR suspicious_network="true" OR suspicious_file="true"
| stats count by host, user, process_name, process_cmd_line, parent_process_name, dest_host, dest_port, file_path, suspicious_child, suspicious_network, suspicious_file
| sort -countDetects trivy processes spawning suspicious children (reverse shells, interpreters), making unexpected outbound network connections, or writing files to temp directories — indicators of trojanized Trivy (CVE-2026-33634).
Data Sources
Required Sourcetypes
False Positives & Tuning
- Trivy downloading DB updates to operator-configured non-standard mirror endpoints
- CI/CD pipeline scripts wrapping trivy with bash and piping output to curl for reporting
- Trivy plugins writing scan results to /tmp before forwarding to SIEM
- Security scanning infrastructure where trivy runs with broad network access by design
Other platforms for CVE-2026-33634
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Trivy Binary Hash Verification Failure Simulation
Expected signal: ProcessRollup or DeviceProcessEvents event for /tmp/trivy-test with a SHA-256 hash differing from the official trivy binary hash; file creation event for /tmp/trivy-test.
- Test 2Trivy Spawning Reverse Shell Child Process
Expected signal: ProcessRollup event showing trivy (or trivy-named process) as parent of nc/netcat; NetworkConnect event for local port 14444.
- Test 3Trivy Unexpected Outbound Network Connection
Expected signal: NetworkConnect event from a process named 'trivy' (via exec -a) to 169.254.169.254 port 80; DnsRequest or direct IP connection telemetry.
- Test 4Trivy Writing Dropper to Temp Directory
Expected signal: FileCreate event showing a trivy-named process writing an executable file to /dev/shm/; file hash and permissions captured in endpoint telemetry.
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