Dependency Hijacking

What Dependency Hijacking Means in Practice

Dependency hijacking is a software supply chain attack against the trust boundary between developers and package ecosystems. The danger is not just that malicious code can arrive through a seemingly legitimate dependency, but that it can arrive in a form that fits normal build and update workflows, making compromise look routine until the payload executes.

This attack pattern is closely related to dependency confusion, typosquatting and package takeover. In all of them, the attacker’s goal is to insert code into a path developers already trust, so the compromise is delivered through ordinary installation, resolution or publishing behavior rather than through an obviously suspicious file transfer.

How Hijacked Dependencies Enter Builds

Dependency hijacking usually succeeds when a package is abandoned, expired, unmaintained or otherwise vulnerable to takeover. Once an attacker controls the package name or distribution channel, they can replace benign content with backdoors, credential theft, persistence logic or other hidden functionality that is pulled into builds and released downstream.

The supply chain risk is greatest when package selection is implicit, when dependency sources are too broad, or when external packages can shadow internal ones. Controls that narrow resolution paths, pin approved artifacts and separate trusted internal packages from public ecosystems reduce the chance that a build system will silently accept the wrong package.

NHIMG’s OWASP CI/CD Top 10 CICD-SEC-3 Dependency Chain Abuse Guide is a natural reference point for the package-resolution and build-integrity issues that make this attack work.

Why It Matters for Software Supply Chain Security

Dependency hijacking matters because it can compromise many downstream consumers at once. A single taken-over package may be imported into multiple services, build pipelines or release artifacts, turning one malicious update into broad exposure across development, test and production environments.

It also creates a trust problem that is hard to spot from code review alone. The malicious package may resemble a normal maintenance update, so security teams often need provenance checks, dependency inventory and source validation rather than simple signature-based detection. OpenSSF is a useful external reference for open source supply chain security guidance and ecosystem hardening.

The compromise may also expose secrets or session material during build and test execution if the package is allowed to run install scripts or access environment variables. That makes dependency hijacking more than a code integrity issue, because the attacker can pivot from package execution to broader environment abuse.

LiteLLM PyPI package breach is a concrete example of how a malicious package can become a supply chain compromise with credential impact.

How Organisations Reduce Exposure and Recover

Reducing exposure starts with knowing which dependencies are actually in use, where they come from, and whether any of them are abandoned or externally maintained. From there, organisations typically harden package resolution, restrict install-time execution, prefer internal proxies or curated registries, and verify artifact integrity before release.

If hijacking is suspected, teams should treat both the package and any builds that consumed it as potentially compromised. That means reviewing recently published artifacts, checking for unusual outbound connections or script execution during install, and rotating any secrets that may have been exposed in the build environment or downstream runtime.

Because package takeover is a supply chain problem, remediation is usually broader than simply deleting the bad dependency. Organisations often need to replace the package, validate affected releases, and confirm that no downstream consumers inherited the malicious code through transitive dependencies.

Risk and Threat Considerations

Dependency hijacking is dangerous because it abuses trust in the software supply chain itself. The attacker is not trying to break a strong control at runtime, but to become the trusted dependency that developers and automation pull in without suspicion.

Failure mechanism: A package name, distribution path or maintainer relationship becomes available for takeover, then build systems ingest the malicious replacement as if it were legitimate.

Impact: The result can be backdoors, credential theft, malware persistence, poisoned releases and a compromise that propagates into every downstream system that consumes the affected artifact.

Practitioner Guidance

Why practitioners should care: Dependency hijacking is a release integrity problem, not just a repository hygiene issue. Ownership of package sourcing, dependency review and artifact provenance should be explicit, because the attacker’s entry point is often the software delivery process itself.

What to watch for: Pay special attention to abandoned packages, sudden maintainer changes, unexpected dependency additions and install-time scripts. These are the points where a legitimate-looking dependency can turn into a delivery vehicle for malicious code.

Related resources from NHI Mgmt Group

• Why do delayed payloads and dependency hijacking increase risk in supply chain attacks on npm?
• Dependency Repository Hijacking
• When does a dependency compromise become an identity incident?
• How can security teams reduce the risk of session hijacking in SaaS environments?