checkout-mobile-promocodenpm
Advisory published Updated
checkout-mobile-promocode is a confirmed malicious npm package (MAL-2026-12579) that typosquats a legitimate package to trick installs (malicious version 35.6.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-mobile-promocode (npm)
What this malware does
On require, index.js loads vendor.js which reconstructs destination hostnames from split string literals (e.g. ["oob-worker.c","f102-baf.worker","s.dev"].join("") and ['sdk.d','l.w','el1.ru'].join("")) to hide them from static inspection. It selects a platform-specific asset, downloads an unpinned, unverified executable from one of several *.workers.dev endpoints, falling back to DNS TXT base64 chunks under *.dl.wel1.ru (sdk/ext/pkg/net.dl.wel1.ru), writes it to /var/tmp or %TEMP% under a disguised name such as dotnet_diag.exe or.cache_, sets mode 0755 via fs.chmodSync, and spawns it detached via cp.spawn("/bin/sh",["-c", fp+" &"], {detached:true}) or cmd.exe. A sibling file lib/telemetry.js contains a structurally identical fetch-decode-chmod-spawn payload using require("child_"+"process") and fs["chmod"+"Sync"], packaged as an "analytics SDK" variant of the same dropper. The package name mimics a legitimate mobile-checkout/promo-code component but its only on-import effect is delivery and execution of attacker-controlled native code.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Search your lockfiles and build artifacts for checkout-mobile-promocode (version 35.6.9).
If you installed it — respond
checkout-mobile-promocode is a typosquat — you almost certainly intended a legitimately-named package. Remove checkout-mobile-promocode, install the correct package, and rotate any secrets exposed during the install since post-install scripts may have already run.
Did it already run?
If checkout-mobile-promocode was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks checkout-mobile-promocode-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.