Malicious packages are software components intentionally designed or compromised to perform harmful actions on a system where they are installed or executed. Unlike legitimate software with unintentional vulnerabilities, these packages harbor malicious intent.

**Key Characteristics of Malicious Packages:**

*   **Intent:** Designed to steal data, gain unauthorized access, disrupt operations, or cause other harm.
*   **Deception:** Often masquerade as useful utilities, popular libraries (sometimes through typosquatting – using names very similar to legitimate packages), or appear as benign, unmaintained packages that an attacker takes over.
*   **Distribution:** Commonly distributed through public software repositories (e.g., npm, PyPI, Maven Central, RubyGems, NuGet), relying on developers to unwittingly include them in their projects. They can also be injected into legitimate packages if an attacker gains control of the package owner's account or the build infrastructure.
*   **Payloads:** Can include various types of malware such as spyware, ransomware, credential stealers, crypto miners, backdoors, or code that facilitates further attacks.

**Common Objectives:**

*   **Data Exfiltration:** Stealing sensitive information like user credentials, API keys, financial data, personal identifiable information (PII), or intellectual property.
*   **System Compromise:** Gaining unauthorized control over developer machines, build servers, or end-user devices.
*   **Resource Abuse:** Using compromised systems for activities like cryptocurrency mining or participating in DDoS botnets.
*   **Lateral Movement:** Using an initial foothold to move deeper into an organization's network.
*   **Financial Theft:** Directly stealing funds or facilitating financial fraud.

Identifying and mitigating the threat from malicious packages is a critical aspect of modern software supply chain security.