Skip to content

Malicious code in crypto-tax-export (RubyGems)

Malware Published Oct 11, 2026 to the GitHub Advisory Database • Updated Oct 11, 2026

Package

bundler crypto-tax-export (RubyGems)

Affected versions

= 0.9.1

Patched versions

None

Description

Source: amazon-inspector (d2481974cbcc361b29455129afea878124dafde18097efca0a87235df57f3bea)

The gem's native-extension build script ext/crypto_tax_export/extconf.rb runs during gem install. Before executing its payload it performs sandbox/analysis-evasion checks (CI environment variables, ephemeral/generated hostnames and usernames, known analysis paths, system uptime under 30 minutes, and presence of developer-signal files such as ~/.ssh, ~/.gem/credentials, and ~/.gitconfig). When those checks indicate a real developer workstation, it double-forks a detached, stdio-closed daemon that sleeps a randomized 20-40 minutes and then executes eval(Base64.decode64(...)) on an embedded payload that opens a /bin/sh reverse shell via TCPSocket to the hardcoded bare IP 45.138.12.177:8089 in a reconnect loop. The create_makefile call is a stub targeting an unrelated name (bitcoin_rpc_lite_native), the shipped lib/crypto_tax_export.rb contains only trivial VERSION/build_id/healthy? methods with no tax-export functionality, and the README is for a different package (bitcoin-rpc-lite), indicating the extension script is the gem's sole purpose and the advertised identity is cover.


Credit: OpenSSF (source)

References

Published to the GitHub Advisory Database Oct 11, 2026
Reviewed Oct 11, 2026
Last updated Oct 11, 2026

EPSS score

Weaknesses

Embedded Malicious Code

The product contains code that appears to be malicious in nature. Learn more on MITRE.

GHSA ID

GHSA-7qmm-9mrq-vf4q

Source code

No known source code
Improvements are not currently accepted on this advisory because this package is malware and has no patched versions. If there is something to change, please open an issue at https://github.com/github/advisory-database/issues.