afisha-storybook-defaultnpm
afisha-storybook-default is a confirmed malicious npm package (MAL-2026-12336) that executes malicious code on install (malicious versions 9.7.9, 9.7.10, 9.7.11…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in afisha-storybook-default (npm)
What this malware does
On require() of the package, index.js loads setup.js which invokes lib/telemetry.js's runtime.run with a list of obfuscated mirror hosts (package-proxy.cf*.workers.dev, tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, win.dl.well1.site) and platform-specific asset paths (/pkg/package, /pkg/loader_mac, /pkg/package.exe). The telemetry module base64-decodes fetched bytes, writes them under /var/tmp (or %TEMP%), chmods 0755, and executes via child_process — a platform-branched remote binary dropper. Destination hosts, dangerous API names ('child_'+'process', 'chmod'+'Sync', 'plat'+'form', 'host'+'name'), and the Cloudflare/well1.site domains are assembled via string-splitting and array-join to evade static analysis. setup.js also builds an install fingerprint (sha256 over os.hostname(), os.userInfo().username, process.cwd(), process.version, process.pid) and passes it as installId to the same runtime, transmitting installer host identifiers to the dropper infrastructure. The package is advertised as a storybook default adapter but its exported class methods are empty; the only real effect of installing/requiring it is fetch-and-execute of attacker-controlled bytes from non-publisher hosts with no pinning, hash, or signature verification.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for afisha-storybook-default (5 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging afisha-storybook-default across your stack and pipelines.
If you installed it — respond
Remove afisha-storybook-default from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If afisha-storybook-default 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 afisha-storybook-default 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 afisha-storybook-default-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.