tw-pkgprobe-7731npm
tw-pkgprobe-7731 is a confirmed malicious npm package (MAL-2026-14062) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.0, 1.0.1, 1.0.3…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tw-pkgprobe-7731 (npm)
What this malware does
On preinstall/postinstall, probe.js checks whether cwd matches a Twilio Serverless build path (/tmp/AC<32hex>/) and, if so, copies daemon.js to /tmp/.npm-helper.js and spawns it as a detached background process via process.execPath. The daemon polls /tmp every 80ms for sibling directories whose names match Twilio account SIDs (AC followed by 32 hex chars) and POSTs the discovered account/service/package identifiers to a hardcoded https://webhook.site/cc08d9d9-232a-42a2-8d55-0f75cb5e0e67 endpoint. For matching directories it captures process.env.ACCOUNT_SID and a prefix of process.env.AUTH_TOKEN and writes them to a proof file. The daemon also writes an 'injected-by-other-tenant' module into sibling build trees and appends a payload (marked /XTENANT_PROOF/) into runtime-handler's main file so that a different tenant's execution context runs attacker-authored code that captures that tenant's ACCOUNT_SID and AUTH_TOKEN prefix. package.json description and code comments frame the package as an authorized Twilio HackerOne bug-bounty probe; that self-labeling does not change the mechanical behavior, which is an install-time dropper, cross-tenant code injection, and remote exfiltration to a third-party webhook endpoint.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for tw-pkgprobe-7731 (9 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tw-pkgprobe-7731 across your stack and pipelines.
If you installed it — respond
tw-pkgprobe-7731 is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If tw-pkgprobe-7731 was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks tw-pkgprobe-7731 before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks tw-pkgprobe-7731-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.