Over 100,000 websites were compromised in a recent Polyfill supply chain attack, exposing significant vulnerabilities in third-party script integration. This incident highlights the growing danger of supply chain attacks, where attackers exploit flaws in software supply chains to break into systems.
What is a Supply Chain Attack?
A supply chain attack occurs when a threat actor enters an organization’s supply chain to compromise its operations, products, or services. Instead of directly attacking the primary target, the attacker focuses on a less secure element within the supply chain—such as a third-party vendor, software provider, or hardware supplier.
Once the attacker compromises the weaker link, they can use this access to infiltrate the main target, often with devastating effects.
Client-Side and Server-Side Supply Chain Attacks
Supply chain attacks can significantly disrupt both individual user systems and broader organizational infrastructures. These attacks can be categorized into client-side and server-side types, each targeting different aspects of the supply chain and posing unique risks and challenges.
Client-Side Supply Chain Attacks
Client-side supply chain attacks target the end-user environment. These attacks aim to exploit vulnerabilities in software or components running on users’ devices. Attackers might compromise the update mechanisms of client software to distribute malicious updates or introduce harmful plugins and extensions into software marketplaces.
For instance, an attacker might infiltrate a popular app store and distribute a version of an app embedded with malware.
Another common approach involves exploiting vulnerabilities in client-side scripts or web applications accessed through web browsers, such as through Cross-Site Scripting (XSS) attacks. These attacks often require some user interaction, such as installing software or clicking on malicious links, but can lead to severe consequences like data breaches or system compromises if successful.
Server-Side Supply Chain Attacks
Server-side supply chain attacks, on the other hand, target the servers and infrastructure that manage and distribute software and services. Attackers might compromise the build environment or source code repositories of server-side software, injecting malicious code into the software before it is distributed. This type of attack can have widespread impact, affecting multiple clients who use the compromised software.
Another common method involves exploiting vulnerabilities or backdoors in third-party components integrated into server applications.
Additionally, server-side attacks can involve compromising the server infrastructure itself, such as cloud services or hosting providers, leading to potential unauthorized access to data across multiple clients.
How Does a Supply Chain Attack Work?
A software supply chain attack targets the various stages of software development, distribution, and maintenance to insert malicious code or compromise the software before it reaches end users. Here’s a detailed look at how such attacks work:
Targeting the Development Phase
In this stage, attackers aim to infiltrate the software development process. They may:
Compromise Source Code: Attackers gain unauthorized access to the source code repository. By modifying the source code, they can insert malicious code that gets compiled into the final product.
Infect Development Tools: Attackers may compromise development tools, such as integrated development environments (IDEs) or code analyzers, to inject malware during the build process.
Manipulate Build Systems: The build system, responsible for compiling and assembling code, can be targeted to insert malicious components into the software.
Infiltrating the Distribution Pipeline
After development, the software moves into distribution. Attackers can:
Compromise Update Mechanisms: If an attacker gains control over the update mechanism or the server distributing software updates, they can deliver a compromised update to users. This can spread malware widely.
Tamper with Software Repositories: By breaching repositories (e.g., GitHub), attackers can upload malicious versions of software components. Users end up downloading and using these compromised components without realizing it.
Exploiting Third-Party Dependencies
Modern software often relies on third-party libraries and components. Attackers may:
Inject Malicious Code into Dependencies: By compromising popular open-source libraries or packages, attackers can distribute malicious code widely. For instance, an attacker might add a backdoor to a widely used library that, when integrated into various applications, grants them access to multiple systems.
Manipulate Package Managers: Attackers may exploit vulnerabilities in package managers (e.g., npm, PyPI) to distribute malicious packages or alter legitimate ones.
Social Engineering and Phishing
In addition to technical methods, attackers often use social engineering to facilitate supply chain attacks:
Phishing Developers: Attackers may use phishing emails or tactics to trick developers into providing access credentials or inadvertently introducing malware into the development environment.
Targeting Supplier Relationships: By compromising suppliers or partners with access to the software development or distribution process, attackers can introduce malicious code into the software supply chain.
Famous Supply Chain Attacks
Several high-profile supply chain attacks have made headlines in recent years, highlighting the severity of this threat:
Polyfill[.]io (2024): Polyfill, a library that assists older browsers support new features, is commonly used via the cdn.polyfill.io domain. In February 2024, the Chinese company Funnull acquired the domain and GitHub account, then modified Polyfill.js to insert malicious code into any site that used it. This attack redirected users to scam sites, stole sensitive data, and allowed unauthorized code execution. Get the full details in our coverage of the Polyfill supply chain attack.
SolarWinds (2020): One of the most notorious supply chain attacks, the SolarWinds breach involved attackers compromising the software update process of the Orion IT management platform. This allowed them to distribute a backdoor to thousands of organizations, including government agencies and Fortune 500 companies.
CCleaner (2017): Hackers infiltrated the build environment of the popular PC cleaning tool CCleaner, embedding malicious code in the software that was later distributed to millions of users through legitimate updates
Why Supply Chain Attacks Are Hard to Detect?
Exploitation of Trust: Attackers often target reputable suppliers or services that organizations trust. By compromising these trusted sources, the malicious activity appears legitimate and goes unnoticed.
Interconnected Systems: As organizations increasingly connect with suppliers and partners, the attack surface grows. A breach in one vendor can potentially grant attackers access to multiple organizations within the supply chain.
Subtlety and Persistence: Malicious components are designed to blend with normal processes and can remain dormant for extended periods. This subtle integration makes it challenging to detect their presence before they activate.
Complex Supply Chains: Modern supply chains involve numerous layers of suppliers, vendors, and partners. Due to the complexity of these networks, tracing the origin of a breach or identifying vulnerabilities throughout all components is difficult.
Evasion Techniques: Attackers employ encryption, obfuscation, and other techniques to hide malicious code. These methods prevent traditional security tools from identifying and analyzing the threat effectively.
Insider Threats and Social Engineering: Insiders within organizations or partner companies may unintentionally or deliberately aid attackers. Social engineering tactics exploit human psychology to gain access or manipulate employees, complicating detection efforts.
Lack of Visibility and Monitoring: Organizations may have limited visibility into the security practices and configurations of third-party components they use. Inadequate monitoring and threat detection tools further hinder the ability to spot and respond to attacks.
Best Practices to Prevent Software Supply Chain Attacks
Implement Rigorous Security Controls: Ensure that all stages of the software development lifecycle, from coding to deployment, include security checks and controls. This includes code reviews, automated security testing, and vulnerability scanning.
Secure the Development Environment: Protect the development environment from unauthorized access and ensure that code repositories and build systems are secured.
Monitor Dependencies: Regularly monitor and update third-party libraries and components. Utilize tools to scan for known vulnerabilities in open-source dependencies and promptly apply patches when they become available.
Conduct Supply Chain Risk Assessments: Review the security posture of your suppliers and partners. Ensure they comply with security best practices and have safeguards in place to secure their supply chains.
Implement Zero Trust Architecture: Adopt a zero-trust approach that assumes no implicit trust and requires continuous verification of all entities accessing the network or systems.
Educate and Train Staff: Ensure developers and IT staff receive continuous education on current threats and effective practices for protecting the software supply chain.
How AppTrana WAAP Mitigates Supply Chain Attacks?
AppTrana WAAP provides client-side protection that effectively defends against supply chain attacks targeting your website’s front-end components. It continuously monitors JavaScript activity to identify and mitigate supply chain risks, including client-side attacks like formjacking, Magecart, and digital skimming that exploit vulnerabilities in your website’s third-party integrations.
By implementing Content Security Policy (CSP) rules and JavaScript blocking, AppTrana WAAP prevents malicious scripts from executing and protects sensitive customer data from theft. The solution provides detailed visibility into JavaScript usage, helping to pinpoint and address vulnerabilities quickly.
AppTrana offers two modes for managing JavaScript activity to balance security and usability effectively:
- Detect Only Mode: This mode provides a comprehensive list of all JavaScript activity on your site without blocking any scripts. It allows you to monitor and review all JavaScript interactions, helping you understand potential threats without impacting user experience.
- Protected Mode: In this mode, AppTrana actively blocks the malicious JavaScript identified. This ensures that harmful scripts are prevented from executing, while the regular functionality of your site remains intact.
Learn more in our Supply Chain Attack Fundamentals webinar, covering attack basics, prevention tips, and PCI 4.0 compliance for client-side security.
