What does the dolyame-ui-button malware do?

Package advertises itself as a React UI button but its index.js unconditionally requires _bootstrap.js on module load. _bootstrap.js downloads a platform-specific binary from string-array-obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev and siblings), writes it to /var/tmp or %TEMP% under a disguised name (.cache_ on Unix, dotnet_diag_ .exe on Windows), chmods 0755 on Unix, and spawns it detached via /bin/sh -c or cmd.exe /c start /b. If the HTTPS fetch fails, the bootstrap falls back to a DNS-over-TXT covert channel against *.dl.wel1.ru: it queries a chunk count from c. , batches per-chunk TXT queries at 0. ..N. , base64-concatenates the re

Which versions of dolyame-ui-button are malicious?

The following npm versions of dolyame-ui-button are flagged malicious: 35.9.6. Treat any of these as compromised.

How do I remediate dolyame-ui-button if I installed it?

dolyame-ui-button establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed dolyame-ui-button — how do I know if it already compromised me?

If dolyame-ui-button 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.

Is dolyame-ui-button part of a known attack campaign?

Yes — dolyame-ui-button is associated with the IN-MAL-2026-015633 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find dolyame-ui-button across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for dolyame-ui-button (version 35.9.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dolyame-ui-button across your stack and pipelines.

Malicious package

dolyame-ui-buttonnpm

dolyame-ui-button is a confirmed malicious npm package (MAL-2026-13139) that opens a backdoor for remote access (malicious version 35.9.6). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in dolyame-ui-button (npm)

MAL-2026-13139

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall dolyame-ui-button

What this malware does

Package advertises itself as a React UI button but its index.js unconditionally requires bootstrap.js on module load. bootstrap.js downloads a platform-specific binary from string-array-obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev and siblings), writes it to /var/tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnet_diag<hex>.exe on Windows), chmods 0755 on Unix, and spawns it detached via /bin/sh -c or cmd.exe /c start /b. If the HTTPS fetch fails, the bootstrap falls back to a DNS-over-TXT covert channel against *.dl.wel1.ru: it queries a chunk count from c.<domain>, batches per-chunk TXT queries at 0.<domain>..N.<domain>, base64-concatenates the responses, and writes and executes the resulting binary. C2 hostnames are reassembled at runtime from split-and-join arrays, and cover-story comments ("Shuffle endpoints to distribute load", "SHA-256 integrity check") accompany code that performs no integrity verification. The behavior is unrelated to any UI component functionality and grants the publisher arbitrary code execution on any host that imports the package.

Malicious versions

1 flagged

35.9.6

Indicators of compromise (SHA-256)

db5cddb74df42d94fc066ba42a052c4cbe1cd5ca87de968a7684fab3694fba66

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for dolyame-ui-button (version 35.9.6). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging dolyame-ui-button across your stack and pipelines.
If you installed it — respond
dolyame-ui-button establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If dolyame-ui-button 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-button 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

No. dolyame-ui-button on npm has been identified as a malicious package (version 35.9.6 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015633

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks dolyame-ui-button-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database