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 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.

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?

Search your lockfiles and build artifacts for dolyame-ui-button (version 35.9.6).

Malicious package

dolyame-ui-buttonnpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

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
Search your lockfiles and build artifacts for dolyame-ui-button (version 35.9.6).
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 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

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

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