dolyame-ui-postcsscustompropertiesnpm
dolyame-ui-postcsscustomproperties is a confirmed malicious npm package (MAL-2026-13595) that typosquats a legitimate package to trick installs (malicious version 35.8.1). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in dolyame-ui-postcsscustomproperties (npm)
What this malware does
On require() of the package, shim.js and lib/telemetry.js (reached via the main entry) select a platform-specific payload, download a binary over HTTPS from string-split Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev), and fall back to reassembling base64 chunks retrieved from DNS TXT queries against *.sdk.dl.wel1.ru. The fetched bytes are written to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmod 0755, and detached-spawned via /bin/sh -c or cmd.exe. Destination hosts, module names, and API names are string-split and reassembled at runtime (require("child_"+"process"), fs["chmod"+"Sync"], hostnames joined from arrays) to defeat static inspection. The package name typosquats postcss-custom-properties and the dropper is labelled as an 'Analytics SDK' / 'telemetry' module.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
TyposquatFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for dolyame-ui-postcsscustomproperties (version 35.8.1). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dolyame-ui-postcsscustomproperties across your stack and pipelines.
If you installed it — respond
dolyame-ui-postcsscustomproperties is a typosquat — you almost certainly intended a legitimately-named package. Remove dolyame-ui-postcsscustomproperties, 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 dolyame-ui-postcsscustomproperties 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 dolyame-ui-postcsscustomproperties 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 dolyame-ui-postcsscustomproperties-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.