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.
New SLEEPWALKER Backdoor Waits for One Crafted Packet, Then Runs Its Own Bytecode
A new Windows backdoor dubbed SLEEPWALKER hides as ESET Management Agent's dpapi.dll, waits for a crafted network packet, then executes custom 23-instruction bytecode.
Researcher Dominik Reichel documented SLEEPWALKER, an unsigned 59,904-byte 64-bit Windows DLL that side-loads into ESET Management Agent's ERAAgent.exe while impersonating dpapi.dll. The implant monitors every network interface indefinitely for a specifically crafted trigger packet, then executes commands written in a custom 23-instruction bytecode language over six transports, including TCP, UDP, ICMP, SMB named pipes, raw promiscuous capture, and VMware VMCI. It has no embedded infrastructure, makes no outbound connections of its own, and requires prior local administrator access to install; no victims, attribution, or in-the-wild deployment are confirmed. Reichel assesses the design as consistent with a targeted, well-resourced operation, while ESET calls the scenario's security relevance negligible since it provides no new access path.