{"id":"MAL-2026-17608","summary":"Malicious code in lightning-invoice-utils (RubyGems)","details":"RubyGems runs this gem's native extension script `ext/lightning-invoice-utils/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.\n\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (b1c7aa63129491dc29eaf240d8f4ae910733b8f6f34192279c119c3cb585c68d)\nThe gem declares a native extension (extconf.rb) that is auto-executed by `gem install`, but the shipped C stub `Init_LightningInvoiceUtils` is empty — the native-extension slot is a cover. extconf.rb base64-decodes an embedded Ruby payload whose destination URL is XOR-obfuscated with a 4-byte key, downloads a tarball over plain HTTP to `/tmp/.w1.tgz`, extracts to `/tmp/.w1`, and executes `bash /tmp/.w1/wg_install.sh` in a double-forked detached process with output redirected to /dev/null. Execution is gated by anti-analysis checks that suppress the payload in CI, on hostnames matching `uvm|firecracker|sandbox|vagrant|fc[_-]?vm`, on generated analyst usernames (`uA\\d+`, `sandbox|tester|analys|scanner`), when running from `/tmp`, `/var/tmp`, `/opt/rubygems`, or `/workspace/`, when `/proc/uptime` is under 1800 seconds, and unless developer-credential paths (`~/.ssh`, `~/.gitconfig`, `~/.npmrc`, `~/.gem/credentials`, `~/.bundle`) are present. The advertised BOLT11 invoice-decoding functionality is not implemented in the shipped library code — the package exists to deliver the dropper to developer machines holding SSH keys and registry credentials.\n","modified":"2026-10-05T23:45:03.707968495Z","published":"2026-10-05T09:30:00Z","database_specific":{"iocs":{"ips":["45.138.12.177"],"urls":["http://45.138.12.177:8092/wgkit.tar.gz"],"files":[{"source":"PACKAGE_ARCHIVE","digests":{"sha256":"44f35c300060b3092f93454fc16c802623329b9ba270f8e4a87ff2679115bf63"},"note":"Native extension script that RubyGems runs at install time. It gates on the environment and starts the payload.","paths":["ext/lightning-invoice-utils/extconf.rb"]},{"note":"Second-stage archive and install script downloaded and run by the payload.","paths":["/tmp/.w1.tgz","/tmp/.w1/wg_install.sh"],"source":"DROPPED"}]},"malicious-packages-origins":[{"modified_time":"2026-10-05T15:59:12Z","sha256":"b1c7aa63129491dc29eaf240d8f4ae910733b8f6f34192279c119c3cb585c68d","source":"amazon-inspector","versions":["1.0.0"],"id":"IN-MAL-2026-021066","import_time":"2026-10-05T16:22:56.12583596Z"}]},"references":[{"type":"PACKAGE","url":"https://rubygems.org/gems/lightning-invoice-utils/versions/1.0.0"},{"type":"REPORT","url":"https://safedep.io/rubygems-crypto-gems-install-time-reverse-shell/"}],"affected":[{"package":{"name":"lightning-invoice-utils","ecosystem":"RubyGems","purl":"pkg:gem/lightning-invoice-utils"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.0"],"database_specific":{"cwes":[{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"},{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"sha256":"44f35c300060b3092f93454fc16c802623329b9ba270f8e4a87ff2679115bf63","tlsh":"0e51dc5a8b8355f54db1d0d044359412fb667b0e60689d74f3de0868bb55f2ac4f02fd","path":"ext/lightning-invoice-utils/extconf.rb"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/lightning-invoice-utils/MAL-2026-17608.json"}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"},{"name":"SafeDep","contact":["https://safedep.io"],"type":"FINDER"}]}