MAL-2026-17607 Malicious code in lightinng-invoice (RubyGems)

RubyGems runs this gem's native extension script ext/lightinng-invoice/extconf.rb during gem install. The script exits without action on CI runners and sandboxes, based on CI environment variables, the hostname, the username and the working directory. It continues if the system uptime is over 30 minutes and the home directory holds .ssh, .gitconfig, .npmrc, .gem/credentials or .bundle. It then decodes a Base64 Ruby payload and forks twice into a detached process. After 20 to 40 minutes the payload downloads http://45.138.12.177:8092/wgkit.tar.gz to /tmp/.w1.tgz with curl, extracts it to /tmp/.w1/, runs wg_install.sh with bash and deletes both. The payload stores the URL XOR-encoded with the key usv\x9a. The Ruby code in lib/ is a decoy. The RubyGems account reqthrottle_3474 published this gem and 41 others with the same loader on 2026-10-05.

The gem lightinng-invoice is a typosquat of the Lightning/BOLT11 ecosystem (duplicated 'n', homepage lightinng-invoice.dev) whose advertised functionality is a decoy: lib/lightinng-invoice.rb exposes only a static word list and the declared native extension's C source is an empty 55-byte stub (Init_LightinngInvoice(void) {}). The sole operational code is in ext/lightinng-invoice/extconf.rb, which RubyGems auto-executes during gem install. That script evaluates a base64-encoded Ruby payload that XOR-decodes a hardcoded C2 URL (http://45.138.122.177:8092/wgkit.tar.gz), curls the tarball to /tmp/.w1.tgz, extracts it, and runs bash /tmp/.w1/wg_install.sh inside a double-forked detached child so execution survives the installer process. The dropper is gated with explicit anti-analysis checks: it refuses to fire in CI, on ephemeral/sandbox hostnames, under generated analyst usernames, in analysis paths (/tmp, /opt/rubygems, /workspace), when uptime is under 1800 seconds, or when developer-signal files are absent — it specifically requires the presence of ~/.ssh, ~/.gitconfig, ~/.npmrc, ~/.gem/credentials, and ~/.bundle before proceeding, then sleeps 1200+rand(1200) seconds before executing. The targeting pattern and secret-adjacent gating identify developer workstations with credentials as the intended victims.

The OpenSSF Package Analysis project identified 'lightinng-invoice' @ 1.0.0 (rubygems) as malicious.

It is considered malicious because:

• The package executes one or more commands associated with malicious behavior.