16 Typosquatted RubyGems Packages Steal Browser Credentials and Crypto Wallets
Typosquatted RubyGems packages deliver the StubMaker infostealer, stealing browser credentials, crypto wallets, and Telegram data from Windows developers.
OpenSourceMalware discovered a typosquatting campaign on August 15, 2026, tracked as StubMaker, publishing 16 malicious RubyGems packages (e.g., ubnuler, brumdler, brundlef) that imitate popular Ruby dependencies. The gems use the extconf.rb install hook to fetch a 22 MB Rust-based loader from GitHub, which launches a Go-based stealer ("wincfg") containing a DLL that bypasses Chromium's app-bound encryption to extract browser credentials, payment cards, crypto wallets and seed phrases, and Telegram Desktop data. Stolen data is uploaded as a password-protected ZIP to Gofile, with the download link sent over plain HTTP. The same actor also deployed 37 typosquatted npm packages delivering the identical loader and infostealer, and abused RubyGems' namespace reuse to republish malicious versions of yanked gems.
Hackers Target Claude, Cursor and Codex AI Agents to Steal Tokens and Prompt Histories
Gen Digital found infostealers like Amatera and Remus stealing AI coding agent tokens, prompt histories, and MCP configs from infected Windows and macOS machines.
Gen Digital analysts observed Amatera and Remus detections among tens of thousands of protected Windows users over three months, with Amatera targeting Cline and Continue data and Remus targeting Claude, Cursor, and OpenCode. CallbackBeaver added Cursor and Claude to its collection scope with more than 5,000 samples in 30 days, while macOS-focused Djinn Stealer has been associated with Claude, Codex, Gemini, Cline, OpenCode, and Kilo. The stealers harvest access and refresh tokens, prompt histories, and MCP configuration files that can expose source control, ticketing, databases, cloud resources, and sensitive project context for follow-on fraud. Many stealers add targets via remotely managed rules, meaning this is an adaptation of existing infostealers rather than a new vulnerability in the AI tools themselves.
Infostealers Target Claude, Cursor, Codex and Other AI Agents to Steal Credentials and Sensitive Data
Gen Digital researchers report infostealer families Amatera, Remus and CallbackBeaver now harvest Claude, Cursor and Codex agent data, including tokens and MCP configs.
Gen Digital researchers found commodity infostealers extending their collection rules to local AI coding agent data from Claude, Cursor, Codex, Cline, Continue and OpenCode on Windows and macOS. Amatera targets Cline and Continue, Remus targets Claude, Cursor and OpenCode, and CallbackBeaver added Claude and Cursor with more than 5,000 samples observed in 30 days; Djinn Stealer hits Claude, Codex, Gemini, Cline, OpenCode and Kilo on macOS. Stolen data includes access and refresh tokens, prompt histories, conversation databases and MCP configurations holding API keys, potentially exposing connected source-control, cloud and ticketing systems. Remus is assessed as a Lumma Stealer variant using EtherHiding C2 resolution via Ethereum smart contracts.