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Threat video1:00

Miasma Worm in strutil-core RubyGem: Detection & IOCs

strutil-core's install step runs a Bun worm that harvests 51 credential stores: 9 detection rules, 23 IOCs and a free Splunk SPL rule.

Read the full threat intel for Miasma Worm in strutil-core RubyGem: Detection & IOCs →

Chapters

  1. 0:00The hookMalicious gem reads 51 credential stores.
  2. 0:04The storyIt ran during gem install.
  3. 0:10Attack pathA clean seed came first.
  4. 0:25AttributionAttributed to testmetest.
  5. 0:29Indicators of compromise18 indicators to hunt: 2 domains, 1 URL and 7 SHA-256 hashes, and more.
  6. 0:38MITRE ATT&CK techniques18 ATT&CK techniques, from initial access to impact.
  7. 0:43Remediation4 steps now: Isolate any host or CI runner where strutil-core.
  8. 0:50Detection rules9 detection rules, in SPL, KQL and Sigma.
Transcript

0:00Malicious gem reads 51 credential stores.

0:05It ran during gem install.

0:07Removed after about 5 hours.

0:11A clean seed came first.

0:13Then a trojanized build ran.

0:15It harvested 51 credential stores.

0:17Data left via a server, then GitHub.

0:20Fake hooks planted persistence.

0:25Attributed to testmetest. Confidence: low.

0:3018 indicators to hunt: 2 domains, 1 URL and 7 SHA-256 hashes, and more.

0:3918 ATT&CK techniques, from initial access to impact.

0:444 steps now: Isolate any host or CI runner where strutil-core.

0:519 detection rules, in SPL, KQL and Sigma.

0:56Threadlinqs. The unified security engineering platform.