Supply chain attacks: Hidden threats inside your software stack

Modern software development depends a lot on external libraries, frameworks, plugins, and third-party dependence. This helps the modular and reviewing approach teams to build applications rapidly, cheaply, and more efficiently. However, it also opens a new and often poorly protected attack surface: software supply chain.

A supply chain attack does not target the core code of your application directly. Instead, it compromises with reliable external components that you have integrated—they are often pre-installed or drawn during the build. Once infected, these components quietly spread malicious codes in all the systems that use them.

From nation-state actors to opportunistic cybercriminals, attackers take advantage of rapid supply chain weaknesses to achieve wide impact. This blog examines the history, mechanism, detection, exploitation and defense strategies related to the supply chain attacks targeting web applications.

What is a supply chain attack in web applications?

A supply chain attack involves infiltrating a trusted third-party service or component used within your application’s ecosystem. In the context of web applications, this includes:

  • NPM, PyPI, or Maven libraries
  • WordPress plugins
  • Container images (Docker)
  • Build tools and CI/CD pipelines
  • JavaScript CDNs
  • Package managers and repositories

By poisoning the supply chain—the very tools you trust—attackers can stealthily gain access to a wide array of targets without breaking through conventional security controls.

Development and history of supply chain attacks

The supply chain attacks are not a new concept, but their scale and sophistication have developed considerably in the last decade.

1. Target (2013)

The attackers compromised a third-party HVAC seller to achieve access to the internal network of the target. From there, he deployed malware in more than 40 million point-of-sale systems.

2. Event-Stream NPM Attack (2018)

A popular NPM package, event-stream, was compromised after handing over control to a malicious actor. The attacker introduced a dependency that was cut from a specific bitcoin wallet application.

3. Solarwinds (2020)

One of the most high-profile supply chain attacks in history. State-propelled hackers inserted malicious codes into the Orion software of SolarWinds, affecting 18,000+ customers, including US government agencies and Fortune 500 companies.

4. Kodakov (2021)

The attackers achieved access to Kodakov's bash uploader script, quietly exfiltrating credentials from thousands of customer environments.

These incidents suggest that relying on the third-party code without verification is a high-risk perception.

How to work supply chain attacks

In the core, a supply chain attack is effective as it misuses confidence. Developers and companies believe that the software they install they import they import, and the package they update are safe.

Here is the breakdown of the life cycle of attack:

1. Initial agreement

The attacker compromises with a reliable component:

  • Taking control of a popular open-source project.
  • Dissolve a developer's account and inject malicious code.
  • Publishing typo-squatted packages (e.g., requests3 instead of requests).
  • Exploiting vulnerable CI/CD environments.

2. Distribution

Once the malicious update is released, unsuspecting developers and systems pull in the poisoned package during builds or deployments.

3. Execution

The malicious code:

  • Exfiltrates secrets like API keys, database credentials, or cloud tokens.
  • Opens backdoors.
  • Installs malware or ransomware.
  • Monitors user inputs or steals PII.

4. Persistence and Propagation

The malware may hide in the codebase or spread across dependent systems, sometimes remaining undetected for months.

How Attackers Exploit Supply Chains

Here are the most common exploitation methods:

1. Typo-squatting and Dependency Confusion

Attackers publish fake packages with names similar to popular ones. If a developer accidentally installs lodashs instead of lodash, they might unknowingly execute harmful code.

Dependency confusion involves injecting malicious packages into public registries with the same names as internal private dependencies—making automated build tools prioritize public versions.

2. Hijacking Abandoned Packages

Attackers monitor repositories for inactivity. If an open-source project hasn’t been updated in years, they may try to take it over by:

  • Contacting maintainers for access.
  • Brute-forcing account passwords.
  • Leveraging expired domains and emails.

Once inside, they introduce malicious changes in an “official” update.

3. Construction of construction infrastructure

The attackers can infiltrate CI/CD pipelines to modify the build, insert scripts, or leak the environment during the runtime.

4. Malicious plugins or theme

On platforms such as WordPress, thousands of themes and plugins are available. A compromised or malicious plugin can inject the code in user-disk pages, create a backdoor, or perform unauthorized actions.

To detect supply chain attacks

It is extremely challenging to secretly find out due to the nature of supply chain attacks. They often look like regular package updates or developers.

However, here are some ways to increase visibility:

1. Software composition analysis (SCA)

Use the tool to map all dependencies in your codebase—including transitives—and identify the known weaknesses or unexpected updates.

2. Dependency Change Monitoring

Set up alerts when dependencies change unexpectedly or when new versions are published. Sudden spikes in download counts or modifications in previously dormant packages are red flags.

3. Behavioral Monitoring

Deploy EDR (Endpoint Detection and Response) tools or runtime security solutions to observe suspicious activity like

  • Outbound requests to unknown domains.
  • File system modifications during builds.
  • Unusual use of system resources by packages.

4. Integrity Checking

Generate and compare checksums (hashes) of packages or container images. Any unexpected change in hash may indicate tampering.

5. Audit Trails and Version Locking

Maintain full logs of when, who, and how dependencies were updated. Lock versions using package-lock.json, requirements.txt, or pom.xml to prevent automatic upgrades to tampered versions.

Defensive Measures Against Supply Chain Attacks

Supply chain defense isn’t just about firewalls and antivirus software it requires a security-first development mindset.

1. Verify Before You Trust

  • Use packages from verified or official sources.
  • Audit the source code of lesser-known libraries.
  • Prefer well-maintained, active repositories.

2. Use Minimal Dependencies

Avoid bloated dependencies. If you can write 10 lines of code instead of installing a full package, do it. Every added library is a new potential attack vector.

3. Employ SBOM (Software Bill of Materials)

Maintain a complete, trackable list of all components in your software—including version numbers and origin. This becomes critical for incident response.

4. Sign and Verify Artifacts

Use cryptographic signing for packages, container images, and commits. Only deploy code that is signed by trusted keys.

5. Harden Your CI/CD Pipelines

  • Use environment secrets wisely and store them securely.
  • Don’t allow external scripts or packages to run during builds without verification.
  • Isolate build steps in containers or VMs.

6. Implement Continuous Vulnerability Scanning

Automatically scan code repositories, containers, and dependencies for known vulnerabilities and misconfigurations.

7. Educate Your Development Teams

Train developers to understand supply chain risks. Awareness is the first line of defense.

Popular Tools for Supply Chain Security

While this blog doesn’t endorse specific products, here are categories of tools to explore:

  • Dependency Scanners
  • Runtime Behavior Monitors
  • Code Signing Platforms
  • SBOM Generators
  • Container Security Scanners

All of these help secure your software supply chain from development to deployment.

final thoughts

The supply chain attacks represent a paradigm change in cyber security. The attackers no longer need to exploit the login-form login page or classic buffer overflow—they just need to wait for someone to run malicious "NPM installed" or "doors bridge."

Place in Trust Developers Open-SOS communities and third-party equipment should now be combined with rigorous verification, monitoring, and risk management. - Such as web apps, which are more complex and connected, your safety is only as strong as your weakest dependence.

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