critical self propagating worm mcpnpm

Shai-Hulud

Self-replicating npm worm (Sept 2025, plus v2.0 Nov 2025 and Mini Shai-Hulud May 2026). Used TruffleHog to steal cloud/AI credentials; later waves explicitly targeted Claude Code / MCP config files.

Disclosed September 15, 2025

Blast radius hundreds of npm packages

Status remediated

Overview

Shai-Hulud is a self-replicating worm in the npm ecosystem. It spreads through cascading compromise of maintainer accounts, runs TruffleHog to harvest 800+ secret types, and exfiltrates to attacker-created GitHub repos. The MCP tie-in: mcp-knowledge-base was compromised, and Mini Shai-Hulud (May 2026) harvested ~/.claude.json and ~/.claude/mcp.json.

IOC note

ReversingLabs published per-version SHA1 tarball hashes (npm dist.shasum). These identify npm packages, not browser/IDE extensions, and the malicious versions have been purged from npm — search the hash on VirusTotal/MalwareBazaar to retrieve a captured copy.

Affected extensions (3)

Name	Store	ID	Malicious version	Archived
mcp-knowledge-base	mcp	mcp-knowledge-base	0.0.2	no
@ctrl/tinycolor	npm	@ctrl/tinycolor	4.1.1	no
rxnt-authentication	npm	rxnt-authentication	0.0.3	no

Indicators of compromise (129)

sha1	5a87d68716cf9d99ec90835d623559bead2a76d3	[email protected]
sha1	fab6e4df7b80943ae29bb7b4edd003470da6627e	[email protected]
sha1	b65a8f02bcc425e9f43f44c4062e57a7ed0bb4ac	[email protected]
sha1	a134cb5a9c3187c7e2419ce5981bc8365cfbb1d7	[email protected]
sha1	edca8792f335b64b6929ef08b5d9bf812cc9ce77	[email protected]
sha1	88a1b7b4dfe55bfcf33ee73520506596c3b11f05	[email protected]
sha1	4dc5ee4c3152541d892944c7599b81c8d6b1afd6	[email protected]
sha1	cefb886c65d58dec552d217bf2e6bbfff900a067	[email protected]
sha1	0ed8d9cad44182c5e0867c105fb1dcb4b559a87f	[email protected]
sha1	ec85986413119e60684a99f3100c9d481cfdf08c	[email protected]
sha1	287a71e7df71b6c1cc10d51a4c18f8a1ce23cba0	[email protected]
sha1	48932e2c66fb9fd103cdd2a4c0bfb77483061511	[email protected]
sha1	f1c23c1e76acbd07591e4708bc2f2768a9f754f2	[email protected]
sha1	5ce815ae8dfdb07fb5ebbc50643410e5f63daa2a	[email protected]
sha1	caf629df8ec99ba641873e887a9d3e17bb2e040c	[email protected]
sha1	99db340e5444f15bcafe0888122e12776ee353be	[email protected]
sha1	7c1454a3907079182ce7441def94f21e7e3fb554	[email protected]
sha1	967bcd5cf05a814b9e14895183fe1e00fe06c8fd	[email protected]
sha1	c7d64660cd39ab9ae3a57cb2c9bbf7a89cf559c7	[email protected]
sha1	2ad5fdb982e406b6817225f0a4edf30262a8ed3a	[email protected]
sha1	c86e40c248604f06e220675de5ea0af17711fc66	[email protected]
sha1	cb81069ef7b290660f9f640a56cfab33bd5764df	[email protected]
sha1	4c65f7bf4974a2892e2867dad270777cc1b1f0e0	[email protected]
sha1	c5012da7a0588bf39f4666a83ce43e11f70eb655	[email protected]
sha1	0c708c8b4d02903233ce1d3913353e4ab9e33ce9	[email protected]
sha1	8b5f31b22ac158f488179c49e718043e6bef25ef	[email protected]
sha1	8960070bcf368cb548f80756e22170836028897d	[email protected]
sha1	05307d8af5bea87f5ec60aaadcdd7be5a0f2e3fd	[email protected]
sha1	cab67ca4f2051efb640e5b73b5faea6c2b7af4a1	[email protected]
sha1	dcea1fdaa6621072fed6962e3461e18c22f7261d	[email protected]
sha1	1b6704faf237f65c83e1856c1c5f6efa9ec0e9ab	[email protected]
sha1	9dd491b1b2faa10419198cadc25d0b30d46acba2	[email protected]
sha1	8b9873af85a6f4a5ab24d76dd97dc3fa83a53dd6	[email protected]
sha1	757255f78f024ef955de52d63156a56e0a91398b	[email protected]
sha1	b7ba4864a1aab4ba632c9c0fe1fcdc2fb0c268c8	[email protected]
sha1	f1db81c622e9264c7808010fd2eaa585f8766335	[email protected]
sha1	a9bd726a1c567cbf8be371de175298c2ba10b19b	[email protected]
sha1	331c874a34747ac27a0caa5469474f552b0189f3	[email protected]
sha1	74de479293d9a47cce99c13f25e15103d40fbd0f	[email protected]
sha1	899c7632dfc1db4917416ab42a3b66c220728b20	[email protected]
sha1	59e3b10efec96f31c90a15d0b3cdb3c3a3474ed4	[email protected]
sha1	70e30ebb44489fca86d9ddc6f85c3cbb54f3bbbc	[email protected]
sha1	5cf876f82760193d2d068f3c5e1a24c7138002b1	@teselagen/[email protected]
sha1	bb5d7c3f23e1b5218f7a718f0a627cd0e897f39a	@teselagen/[email protected]
sha1	79d8b13567743aa842225f1d4a1a91fe3a1f3af8	@teselagen/[email protected]
sha1	9b9a438091a5647e4ceb336fea424a384756183e	@teselagen/[email protected]
sha1	40b9aa9f98dc6073e04a56fd9d3596e4abefc596	@teselagen/[email protected]
sha1	eab6be69fbc87987a64474f67c237c728d792a70	@teselagen/[email protected]
sha1	bcf8527ac58d7409c7330c617330cc136eb819f1	@teselagen/[email protected]
sha1	1a510a951e0fc186b99e313d94ab6ab72a6cd9d0	@teselagen/[email protected]
sha1	038aea646659592778a4ea13b3dcab6e1f3ca32d	@teselagen/[email protected]
sha1	d8c0d20a17951f0b8a85c7cf5400d98841e17de6	@teselagen/[email protected]
sha1	32547a2862896cb2f96ac23284fc5e979f0e2414	@teselagen/[email protected]
sha1	fd1dd0aee3ccb7fabd751e8a3d3ba99c493391bd	@teselagen/[email protected]
sha1	c8ae5c76dc5837e18736678e928357a575a28a9f	@teselagen/[email protected]
sha1	7299b1adfe9f49d9f9caa14e8765c9ffe7cdd35b	@teselagen/[email protected]
sha1	a28500d7adbb44e9fb29cb64401077ccfa2725ea	@teselagen/[email protected]
sha1	877569099a6509ace5e120c0109b5da7f7a2282f	@teselagen/[email protected]
sha1	066b0294e11a90cfcb11dad16f3d5557712c7ebd	@teselagen/[email protected]
sha1	27ae0e090fb441ef2da0e955f66c4f434f1368a7	@teselagen/[email protected]
sha1	68e74c4250af9845f3c193b74e91124f2888de50	[email protected]
sha1	640376c96617c1845378137b7a1d9cb74928ba20	[email protected]
sha1	933d64001fc0459dae8a0449e08c662c734a6f0b	[email protected]
sha1	c2f0cc5734af74e244ff7ac34ea45387d813a22d	[email protected]
sha1	a87cbf0a4cefbce50aa699641df2b61a833bca97	[email protected]
sha1	a28a7b4cd232a7935fdf9495b439a8d54ececbc6	[email protected]
sha1	e7d43606eb9fa18f4996db691f2086541b9bd3f4	[email protected]
sha1	0490214387616c1265447752310136352545831e	[email protected]
sha1	9459764f29b525e068c890663c79ec7ef81e9496	[email protected]
sha1	602a9c12e35b78e0608a163495b5bddb5c2dc0fe	[email protected]
sha1	d36e5dd827d1b316e641a28bd4d1fb74b209d6f4	[email protected]
sha1	b0fec9e0e1855df3f154f021489848087b5f8762	[email protected]
sha1	711cfa0503a965e901a943798923bd5a181eda67	[email protected]
sha1	4c6aaae6c2f7e6b34e72a35f19ba686a6df76660	[email protected]
sha1	dc3c63c58f1f1fa2117b1657114b5d7e4c44c850	[email protected]
sha1	3c5b060c1a124123a7480cd57d9db98b52a638c3	[email protected]
sha1	d9f7f7f88fbc8094b721968d150af696913fa590	[email protected]
sha1	953dc4903d8a08f21d0a7cf49f01a1fe9f219434	[email protected]
sha1	18e323f15332a80e13037cf71fc632b4a7c79b27	[email protected]
sha1	d3eaea409b77c9497adbf544563a2abb197f1d95	[email protected]
sha1	ddbf3395f4d584e2a788b15061e85c2d17fb1509	[email protected]
sha1	badf1b89443fc68e1369dd753eaeaac784e9df1b	[email protected]
sha1	17b464cbf81e074aaed24eb87c02d567f56dcfce	[email protected]
sha1	d02f0f2ea5c9b1c29e5f6aae4fa0677f99b03cde	[email protected]
sha1	c68054201d511f2135750edaef49958b4587267f	[email protected]
sha1	317c491606e651a49db9873aed3a25fe2d7b9d6f	[email protected]
sha1	f1501a45e6ac7d1e95c8a6ef9f192583b6d91a56	[email protected]
sha1	897513887c92230ff0244cd51cd8f29664df28a5	[email protected]
sha1	f1a932205d020c521ea52de4159d5d340cdb7fcc	[email protected]
sha1	0f2d98464cdaa2211a27977596c0c0652862302a	[email protected]
sha1	784dac6eae8261e32152f667286dc38e53b1bbcd	[email protected]
sha1	527b3bbcbb86e88a2f51199bc21e12aec19bbb62	[email protected]
sha1	cc7371ec3fc1ad9a62cb246e5885f13edf5fdeca	@ctrl/[email protected]
sha1	087e06ddade4a3a91292f550173f8470c49b5c36	@ctrl/[email protected]
sha1	b64401062ed84bacab8d6de8d6865d05978cd713	@ctrl/[email protected]
sha1	61a401e669a33cbd38ca717fda0e6bb86665e9bf	@ctrl/[email protected]
sha1	2eaf147ef0a371050f3f1cec559ab9d2862036ae	@ctrl/[email protected]
sha1	aea3cb5108e29c7869890012d06a7396a8b29ec3	@ctrl/[email protected]
sha1	a5e233a8801faec95d35a703c0ca701e95048b35	@ctrl/[email protected]
sha1	3563ab863a9df12638c628b00c36ca2acee6e547	@ctrl/[email protected]
sha1	48f74f6af4a5932945b41479c734560ace278999	@ctrl/[email protected]
sha1	c4a7f650aa3281fbb8c518eeb5254929e00a3651	@ctrl/[email protected]
sha1	1f86a2dd3636c1b3f6754bc8ad760c1154a8eeee	@ctrl/[email protected]
sha1	d93c8c3688745239be212f87df64edb7e2284910	@ctrl/[email protected]
sha1	8820c2a858b73c91eb9567355dba4b6911bb2eed	@ctrl/[email protected]
sha1	6f6b53f38e2e1880ed82810dc5fce39cdd942155	@ctrl/[email protected]
sha1	cd11335d66bed36e237b91ed2bc1b8ac0dc3c560	@ctrl/[email protected]
sha1	4223c5eb6d4d8b757e8be054c56417611d47098e	@ctrl/[email protected]
sha1	d7e800c37d67d878149fc7a6fb1569a654f928e5	@ctrl/[email protected]
sha1	cc289cc72e44d3863d4d099bc1a597fec17821c2	@ctrl/[email protected]
sha1	35187a7ee832909f901a713be277bb636692f422	@ctrl/[email protected]
sha1	ef42322bb763f24d44c9594c43812aa18c99dfe3	@ctrl/[email protected]
sha1	31a8730a11fc6cbf1bbdd216d7053949e908c50f	@ctrl/[email protected]
sha1	ffd87620395edb43ae3f51bc7b5852e575627721	@ctrl/[email protected]
sha1	c9011fb8316e2cc639099643d42909aa32f5f85b	@ctrl/[email protected]
sha1	d64d6c775c37bf4c1a19c5ec9354f9caff435eaf	@ctrl/[email protected]
sha1	b6003fe43666d12f190d51f5279c44c480dd63e6	@ctrl/[email protected]
sha1	eb901ee6b02a6ce51786241e300a30f82eae6dc5	@ctrl/[email protected]
sha1	93fe3f8a055b4d4000b95c8eecb029293bf6912f	@ctrl/[email protected]
sha1	62092c345d57fe75256d0e2d1d0b694c8bc51bbf	[email protected]
sha1	3ab7860deb3bde7a324c12cbbeb5532442f56709	[email protected]
sha1	932608d1ce4a27c9ee27ff94d68a0b511470eabb	[email protected]
sha1	4e5e70b023b5d8f0983ba69d2fa2788b86df6d54	[email protected]
sha1	382b2e158f2f6a2efc70513bf8c7879715bf908a	[email protected]
sha1	893f7d22e9e2a9f50ae583522bcace960a706a04	[email protected]
sha1	8649b99dd099a48c433f9f3eaafa4f7a70d01816	[email protected]
sha1	1d37200f4644190a94df00cfec8c48bce74691ba	[email protected]
sha1	546d6a18e2f8b4a7229a25afc0c6bb22df008715	[email protected]
sha1	931b4da27e51406a0b49fd547b219dbaf69f3351	[email protected]

Shai-Hulud

Overview

IOC note

Affected extensions (3)

Indicators of compromise (129)

Sources