Over the past 15 months a series of high-profile backdoors, worms and trojans have compromised thousands of npm, PyPI and other open-source packages, exposing millions of downstream projects to remote access, data wiping and credential theft. The article traces incidents from the xz-utils backdoor to self-propagating npm worms, explains how deep dependency trees magnify risk, and outlines immediate steps—pinning versions, auditing dependencies and funding maintainers—to stem the threat.

• The Jia Tan xz-utils backdoor took two years of patient, legitimate-looking contributions to slip in, and was only caught by accident when an engineer noticed a slight SSH slowdown.
• Supply-chain attacks have escalated fast: Shai-Hulud went from hijacking 500 npm packages to infecting 25,000 GitHub repos two months later, complete with a dead-man's-switch data wiper.
• Nation-state actors are now directly involved—North Korea's Sapphire Sleet poisoned Axios (70M weekly downloads) with a RAT, and 1,700 malicious packages across npm, PyPI, Go and Rust have been tied to North Korean groups.
• A typical Node.js app pulls in 800–1,500 transitive dependencies (vs. 40 direct ones), meaning most compromises hit projects three or four layers deep where developers have zero visibility.