typography-stylecssnpm
Advisory published Updated
typography-stylecss is a confirmed malicious npm package (MAL-2026-3776) that opens a backdoor for remote access (malicious version 0.7.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in typography-stylecss (npm)
What this malware does
The package impersonates the legitimate @tailwindcss/typography plugin: README, src/index.js, src/utils.js, and src/styles.js are copied verbatim from the Tailwind Labs plugin, and peerDependencies lists tailwindcss to reinforce the masquerade, but the package is published under the unrelated name typography-stylecss. Appended to src/index.js after the legitimate module.exports = plugin.withOptions(...) is an obfuscator.io-style payload (hex-named identifiers _0x168f6b, _0x3fc27f, etc., with a rotated string table _0x5975). Decoded string-table fragments include platform branching ('win32', 'windows', 'agent-linux-') and a URL path template /agents/<deploymentHash> built against a base URL read from a __SSTAR_API_BASE global, consistent with downloading a platform-specific agent binary and executing it. Because this code sits at module top level, it fires on require('typography-stylecss') / import 'typography-stylecss' — exactly the usage the cloned README instructs developers to add to their tailwind.config.js. Any build or dev server that loads the Tailwind config will trigger the dropper, which fetches and runs an attacker-controlled native binary on the installer's machine.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for typography-stylecss (version 0.7.4).
If you installed it — respond
typography-stylecss 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 typography-stylecss 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 typography-stylecss-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.