{"id":"MAL-2026-17800","summary":"Malicious code in wallet-hd-derive (RubyGems)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (fdfb31a6866dee961d55ad503da9de33a2cf743b52c80862e4380519ad5bef12)\nThe gem is published as a crypto wallet utility but ships no native source; its gemspec declares extconf.rb as an extension so that `gem install` auto-executes it. extconf.rb decodes a base64-encoded Ruby payload and, after checking for sandbox and analysis signals (CI env, ephemeral hostnames, generated usernames matching patterns such as `uA\\d+`/sandbox/tester/analys/scanner, cwd under /tmp, /opt/rubygems, /workspace, low machine uptime) and confirming developer-identifying files (`~/.ssh`, `~/.gem/credentials`, etc.), double-forks a detached process via fork + Process.setsid, sleeps for 20–40 minutes, then opens a TCP connection to 45.138.12.177:8089 and pipes /bin/sh in both directions using TCPSocket and IO.popen/IO.copy_stream. The shipped library at lib/wallet_hd_derive.rb exposes only two no-op methods (`build_id='ok'`, `healthy?=true`) and the README is branded for an unrelated package (`bitcoin-rpc-lite`), confirming the gem exists solely as a delivery vehicle for the install-time backdoor. The destination IP, base64 encoding of the payload, sandbox-evasion gating, and delayed reverse-shell establishment give a remote operator interactive /bin/sh on any developer or CI host that installs the gem.\n","modified":"2026-10-11T14:30:09.912672219Z","published":"2026-10-11T13:47:58Z","database_specific":{"malicious-packages-origins":[{"sha256":"fdfb31a6866dee961d55ad503da9de33a2cf743b52c80862e4380519ad5bef12","source":"amazon-inspector","versions":["0.9.1"],"id":"IN-MAL-2026-021363","import_time":"2026-10-11T14:17:59.436369913Z","modified_time":"2026-10-11T13:47:58Z"}]},"references":[{"type":"PACKAGE","url":"https://rubygems.org/gems/wallet-hd-derive/versions/0.9.1"}],"affected":[{"package":{"name":"wallet-hd-derive","ecosystem":"RubyGems","purl":"pkg:gem/wallet-hd-derive"},"versions":["0.9.1"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"tlsh":"9751775acf8359e55aa1c0c045798012faa3ab0a50646875f3ee0868ff59b26c0f12fe","path":"ext/wallet_hd_derive/extconf.rb","sha256":"10218e975f54a4f11fe3954e1b584a5f05054003bf5773c3c2b8cceaa74ba763"},{"path":"metadata.yaml","sha256":"639cb5f77c70768369244c0d5b86590757eb2974587d812c5eecd673758acb18","tlsh":"0311dd80eb83f43af405d3db98412ba3b373d60cfea53910cae78292438446d6b53122"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/rubygems/wallet-hd-derive/MAL-2026-17800.json"}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}