LWA-2026-10113 MAL-2026-12852 ↗ confirmed malware

bigops-umf-statist@35.3.1

Malicious code in bigops-umf-statist (npm)

T1059.007 · JavaScriptT1059.003 · Windows Command ShellT1105 · Ingress Tool TransferT1071.001 · Web ProtocolsT1102 · Web ServiceT1573 · Encrypted ChannelT1082 · System Information Discovery

Analysis

On require, the package executes a bundled dropper (_runtime.js) that fingerprints the platform/arch and downloads a second-stage binary over HTTPS from Cloudflare Workers endpoints oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf99-9b3[.]workers[.]dev, and oob-worker[.]cf102-baf[.]workers[.]dev (paths /pkg/package, /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe), with a DNS-TXT chunked fallback from the *.dl[.]wel1[.]ru domain (c[.]sdk[.]dl[.]wel1[.]ru observed). The downloaded payload is written to /var/tmp/.cache_<hex> (or dotnet_diag_<hex>.exe under TEMP on Windows), made executable, and launched detached via /bin/sh -c "<path> &" (cmd.exe /c start /b on Windows). Execution is throttled by a /tmp/.analytics_state lock file.

analyzed by
Leitwacht
first seen
Aug 5, 2026, 01:00 PM
analyzed
Aug 5, 2026, 01:02 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.