LWA-2026-8003 MAL-2026-11650 ↗ confirmed malware

@onereach/slack-helpers@1.0.5

Malicious code in @onereach/slack-helpers (npm)

T1059.007 · JavaScriptT1105 · Ingress Tool TransferT1071 · Application Layer ProtocolT1048 · Exfiltration Over Alternative ProtocolT1082 · System Information DiscoveryT1497 · Virtualization/Sandbox Evasion

Analysis

The package's preinstall hook (node setup.mjs) downloads the Bun JavaScript runtime and executes a heavily-obfuscated 727KB bundle (math_init.js) at install time. The obfuscated payload performs host fingerprinting and DNS-tunnel exfiltration: it issues DNS TXT queries to a sinkholed C2 domain (_leitwacht.attached.local.) to exfiltrate host identity data, and fetches remote content that is eval-executed (remote-code-execution dropper). The payload also delays execution past the analysis window and evades sandbox detection. Installing this package runs the payload automatically before any dependency is used.

analyzed by
Leitwacht
first seen
Aug 4, 2026, 11:59 AM
analyzed
Aug 4, 2026, 02:43 PM

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Independently detected by the Leitwacht supply-chain probe. IOCs are defanged. Published CC0. Think this is a mistake? See the dispute policy.