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Vulnerabilities

Vulnerability · MAL-2026-17780

Malicious code in block-explorer-api (RubyGems)

Published Oct 11, 2026 · catalog updated Oct 13, 2026 · Malicious code in block-explorer-api

Open the advisory

Exploitation likelihood is not on this record for MAL-2026-17780. A missing EPSS score is not a low risk. Compare Malicious code in block-explorer-api with the linked advisory before you change production.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Malicious code in block-explorer-api).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
  • EPSS is missing. A missing score is not a low risk.
Severity
Unknown—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
Awaiting synchronization with FIRST
Remediation
Not established
Affected products
RubyGems block-explorer-api

--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (9cfaa3470065369addbb91e3a6c2072e8add334c4d27bff95f91315aa58ae313) The gem's native-extension build script (extconf.rb) decodes a base64-encoded Ruby payload and passes it to eval() inside a double-forked, detached child process with stdio redirected to /dev/null. The decoded payload opens a TCP connection to the hardcoded bare-IP C2 45.138.12.177:8089 and bridges it to /bin/sh via IO.popen and IO.copy_stream in both directions, yielding a full interactive reverse shell on the installer's host under the installing user. Execution is gated by anti-analysis checks that skip CI runners, ephemeral/sandbox hostnames (uvm, firecracker, sandbox, vagrant), generated analyst usernames (uA\d+, sandbox, tester, analys, scanner), common analysis working paths (/opt/rubygems, /tmp, /var/tmp, /workspace), and hosts with uptime under 1800 seconds, firing only when developer-signal files such as ~/.ssh, ~/.gem/credentials, ~/.gitconfig, or ~/.npmrc are present, and after a randomized 20-40 minute delay. The shipped library at lib/block_explorer_api.rb is an inert 10-line stub (VERSION, build_id, healthy?) and the gemspec name (block-explorer-api, authored by generic 'block maintainers') does not match the README, which describes the package as 'bitcoin-rpc-lite'; the install hook contains the entire functional payload while the advertised library does nothing. ## Source: ossf-package-analysis (a5b9d91f1bb472b9d7f227bda95ad5ab56761514d73c202baa3ffdfa4f497cc0) The OpenSSF Package Analysis project identified 'block-explorer-api' @ 0.9.1 (rubygems) as malicious. It is considered malicious because: - The package executes one or more commands associated with malicious behavior.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • RubyGems block-explorer-api0.9.1

How to fix MAL-2026-17780

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

Exploitation likelihood is not on this record for MAL-2026-17780. A missing EPSS score is not a low risk. Compare Malicious code in block-explorer-api with the linked advisory before you change production.

Which versions are affected?

Compare what you have installed with 0.9.1. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 11, 2026 · OpenSSF OSV / OSV Scanner

    Detected

    --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (9cfaa3470065369addbb91e3a6c2072e8add334c4d27bff95f91315aa58ae313) The gem's native-extension build script (extconf.rb) decodes a base64-encoded Ruby payload and passes it to eval() inside a double-forked, detached child process with stdio redirected to /dev/null. The decoded payload opens a TCP connection to t

  2. Oct 13, 2026 · OpenSSF OSV / OSV Scanner

    Updated

    --- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (9cfaa3470065369addbb91e3a6c2072e8add334c4d27bff95f91315aa58ae313) The gem's native-extension build script (extconf.rb) decodes a base64-encoded Ruby payload and passes it to eval() inside a double-forked, detached child process with stdio redirected to /dev/null. The decoded payload opens a TCP connection to t

Sources

References

Freshness

Last verified in this catalog Oct 13, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.