GemStuffer Abuses 150+ RubyGems to Exfiltrate Scraped U.K. Council Portal Data

GemStuffer Abuses 150+ RubyGems to Exfiltrate Scraped U.K. Council Portal Data Ravie LakshmananMay 13, 2026Software Supply Chain / Data Exfiltration Cybersecurity researchers are calling attention to a new campaign dubbed GemStuffer that has targeted the RubyGems repository with more than 150 gems that use the registry as a data exfiltration channel rather than for malware distribution. "The packages do not appear designed for mass developer compromise," Socket said. "Many have little or no download activity, and the payloads are repetitive, noisy, and unusually self-contained." "Instead, the scripts fetch pages from U.K. local government democratic services portals, package the collected responses into valid .gem archives, and publish those gems back to RubyGems using hardcoded API keys." The development comes as RubyGems temporarily disabled new account registration following what has been described as a major malicious attack. While it's not clear if the two sets of activities are related, the application security company said GemStuffer fits the "same abuse pattern," which involves using newly created packages with junk names to host the scraped data. At a high level, the campaign abuses RubyGems as a place to stage the scraped council content. It does this by fetching hard-coded U.K. council portal URLs, packaging the HTTP responses into valid .gem archives, and publishing those archives to RubyGems using embedded registry credentials. In some cases, the payload embedded within the gem creates a temporary RubyGems credential environment under "/tmp," overrides the HOME environment variant, builds a gem locally, and pushes it to RubyGems using the gem command-line interface (CLI), as opposed to depending on pre-existing RubyGems credentials on the target machine. Other variants of the malicious gems have been found to eschew the CLI component in favor of uploading the archive directly to the RubyGems API via an HTTP POST request. Once the new gems have been published, all an attacker has to do is run a "gem fetch" command with the gem name and version to access the scraped data. The novel scraping campaign has been found to target public-facing ModernGov portals used by Lambeth, Wandsworth, and Southwark, with an aim to collect committee meeting calendars, agenda item listings, linked PDF documents, officer contact information, and RSS feed content.It's not clear what exactly the end goals are, as the information appears to be publicly accessible anyway. Socket has assessed that the systematic bulk collection and archival of this data raises the possibility that the attacker may be leveraging the "council portal access as a pivot to demonstrate capability against government infrastructure." "It may be registry spam, a proof-of-concept worm, an automated scraper misusing RubyGems as a storage layer, or a deliberate test of package registry abuse," Socket said. "But the mechanics are intentional: repeated gem generation, version increments, hardcoded RubyGems credentials, direct registry pushes, and scraped data embedded inside package archives." Found this article interesting? Follow us on Google News, Twitter and LinkedIn to read more exclusive content we post. SHARE     Tweet Share Share SHARE  cybersecurity, data exfiltration, Package Registry, Ruby, RubyGems, Software Supply Chain, Web Scraping ⚡ Top Stories This Week 2026: The Year of AI-Assisted Attacks New Linux PamDOORa Backdoor Uses PAM Modules to Steal SSH Credentials Day Zero Readiness: The Operational Gaps That Break Incident Response We Scanned 1 Million Exposed AI Services. Here's How Bad the Security Actually Is Quasar Linux RAT Steals Developer Credentials for Software Supply Chain Compromise PAN-OS RCE Exploit Under Active Use Enabling Root Access and Espionage The Hacker News Launches 'Cybersecurity Stars Awards 2026' — Submissions Now Open Microsoft Details Phishing Campaign Targeting 35,000 Users Across 26 Countries Linux Kernel Dirty Frag LPE Exploit Enables Root Access Across Major Distributions ThreatsDay Bulletin: Edge Plaintext Passwords, ICS 0-Days, Patch-or-Die Alerts and 25+ New Stories ⚡ Weekly Recap: AI-Powered Phishing, Android Spying Tool, Linux Exploit, GitHub RCE and More Critical Apache HTTP/2 Flaw (CVE-2026-23918) Enables DoS and Potential RCE Palo Alto PAN-OS Flaw Under Active Exploitation Enables Remote Code Execution 30,000 Facebook Accounts Hacked via Google AppSheet Phishing Campaign Progress Patches Critical MOVEit Automation Bug Enabling Authentication Bypass Trellix Confirms Source Code Breach With Unauthorized Repository Access Load More ▼ ⭐ Featured Resources [Webinar] Learn How Autonomous Validation Keeps Pace With AI Attacks [Demo] Stop Email Attacks and Protect Cloud Workspace Data Faster [Guide] Get Practical AI SOC Insights to Improve Threat Detection [Demo] Discover How to Control Autonomous Identity Risks Effectively