Glassworm Supply-Chain Attack Hides Malicious Code in Invisible Unicode
Researchers reported a software supply-chain campaign attributed to Glassworm that hid malicious JavaScript inside invisible Unicode characters embedded in GitHub repositories, with the activity also spreading to npm and the VS Code Marketplace. Aikido Security identified at least 151 compromised GitHub repositories, with infections observed between March 3 and March 9, and warned the visible set was likely incomplete because some repositories had already been removed. The technique abuses Unicode Private/Variation Selector ranges such as 0xFE00-0xFE0F and 0xE0100-0xE01EF, causing malicious content to appear as blank space to human reviewers and many code-inspection workflows.
The hidden payload is decoded at runtime and executed through eval(), allowing attackers to conceal a full second-stage loader inside apparently empty strings. Reporting on the campaign says prior Glassworm activity used the decoded script to retrieve follow-on malware via the Solana blockchain as a command-and-control channel, enabling theft of tokens, credentials, and secrets. The attack is notable because the Unicode characters are effectively invisible in editors and terminals, undermining manual review and some static analysis, and because it targeted trusted developer distribution channels rather than end users directly.
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How this story unfolded
4 events from the most recent confirmed update back to the earliest known activity.
Aikido publicly discloses the invisible-code supply-chain campaign
On 2026-03-13, Aikido's findings were publicly reported, detailing how the malware hid payloads in blank-looking Unicode characters and noting that prior related payloads used the Solana blockchain to fetch second-stage code capable of stealing tokens, credentials, and secrets. The disclosure also warned that visual code review and some static analysis tools may miss this technique.
Campaign spreads across npm and VS Code Marketplace
During the same March 2026 campaign, researchers found similar malicious packages on npm and the VS Code Marketplace using the same invisible-Unicode obfuscation technique. Aikido said it detected 151 packages in total, while warning the true number was likely higher because some malicious packages had already been deleted.
Glassworm compromises GitHub repositories with invisible Unicode malware
Between 2026-03-03 and 2026-03-09, a threat actor tracked as Glassworm compromised at least 151 GitHub repositories by hiding malicious JavaScript payloads in invisible Unicode Private Use Area characters. The visible changes were disguised as plausible version bumps and refactors while a decoder reconstructed the hidden code at runtime and executed it via eval().
Aikido first observes invisible-Unicode malware in npm packages
Aikido Security said it first saw the technique in March 2025, when malicious npm packages hid JavaScript payloads inside invisible Unicode variation selector characters. This establishes an earlier origin point for the Glassworm-style supply-chain activity before the larger March 2026 wave.
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I Ran npm install 1,000 Times This Year. Here's Why That Scares Me Now. | HackerNoon
hackernoon.com
Open sourceInvisible malicious code attacks 151 GitHub repos and VS Code - Glassworm attack uses blockchain to steal tokens, credentials, and secrets | Tom's Hardware
tomshardware.com
Open sourceSupply-chain attack using invisible code hits GitHub and other repositories - Ars Technica
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GlassWorm Supply-Chain Worm Hits VS Code, OpenVSX, npm, PyPI, and GitHub
**GlassWorm** was reported as a self-propagating supply-chain malware campaign that spread through developer ecosystems including the **VS Code Marketplace**, **OpenVSX**, **npm**, **PyPI**, and **GitHub** repositories. Reporting indicates the malware abused **invisible Unicode characters** to hide malicious logic inside extensions and packages, allowing payloads to evade casual review while embedding decoder routines, command-and-control markers, and other indicators of compromise. One wave specifically targeted **macOS** users through poisoned OpenVSX extensions, expanding the campaign beyond code repositories into developer workstations. Security researchers and defenders responded by publishing detection guidance and tooling to hunt for GlassWorm artifacts across local Git repositories, VS Code extensions, and package dependencies. The open-source **`glassworm-hunter`** project was released to scan for hidden Unicode payloads, decoder patterns, C2 markers, and known malicious IOCs, reflecting concern that the campaign crossed multiple software distribution channels rather than a single marketplace. The incident highlights a broad software supply-chain intrusion in which trusted developer platforms were used to distribute stealthy malware concealed inside seemingly legitimate code.
May 31, 2026
GlassWorm Supply-Chain Campaign Compromising GitHub Repositories and Packages
The **GlassWorm** campaign is compromising open-source software supply chains by using stolen developer credentials and stealthy code injection techniques to backdoor repositories, packages, and extensions on **GitHub**, **npm**, **PyPI**, and the **VS Code Marketplace**. Reporting describes attackers inserting obfuscated payloads into legitimate projects, including popular repositories and Python codebases, then hiding the malicious logic with tactics such as invisible **Unicode PUA** characters, Base64 encoding, and history rewriting that preserves original commit metadata. The malware is designed to steal secrets, credentials, and access tokens, and in some cases retrieves follow-on payload information through **Solana** transaction memo fields to make exfiltration and command delivery harder to detect. The campaign appears broad and operationally mature, with one report citing at least **151 compromised GitHub repositories** in early March and another describing hundreds of affected Python repositories targeted through force-pushed malicious commits. Attackers reportedly append payloads to files such as `setup.py`, `main.py`, and `app.py`, while earlier access is linked to compromised developer environments, including malicious **VS Code** and **Cursor** extensions used to steal GitHub tokens. The activity affects multiple ecosystems and developer workflows, indicating a sustained supply-chain threat rather than isolated repository tampering, with risks extending to downstream users who install or execute code from infected projects.
Mar 21, 2026
GlassWorm Supply Chain Attack on Visual Studio Code Extensions
A sophisticated supply chain attack has targeted Visual Studio Code (VS Code) extensions, leveraging a self-propagating worm known as GlassWorm. Security researchers at Koi Security discovered the malware after identifying suspicious behavior in an extension called CodeJoy on the OpenVSX marketplace. The worm employs a novel technique using invisible Unicode characters, making the malicious code undetectable to the human eye within code editors. This approach allows the malware to evade traditional detection methods and remain stealthy within compromised extensions. GlassWorm utilizes the Solana blockchain as its primary command-and-control (C2) channel, with Google Calendar serving as a backup C2 infrastructure, enhancing its resilience and making takedown efforts more challenging. The worm has already infected nearly 36,000 developer machines, indicating a significant impact on the developer ecosystem. Once installed, GlassWorm harvests credentials from NPM, GitHub, and Git, enabling it to propagate further by compromising additional packages and extensions. The malware also targets cryptocurrency wallets, seeking to steal digital assets from affected users. Infected systems are converted into SOCKS proxy servers, effectively turning developer machines into part of the attacker's extended C2 infrastructure. Additionally, GlassWorm installs hidden virtual network computing (VNC) servers, granting attackers full remote access to compromised machines. The attack highlights the growing risks associated with open-source marketplaces and the potential for widespread compromise through popular development tools. Security experts emphasize the importance of scrutinizing extension code and implementing stronger guardrails in extension marketplaces to prevent similar attacks. The use of invisible Unicode and blockchain-based C2 channels represents a significant evolution in malware stealth and persistence. The incident underscores the need for developers and organizations to monitor for unusual extension behavior and to regularly audit installed extensions for signs of compromise. The attack also demonstrates the potential for supply chain threats to rapidly scale, given the interconnected nature of developer tools and platforms. As the investigation continues, security vendors and marketplace operators are working to identify and remove malicious extensions and to strengthen defenses against future supply chain attacks.
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