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The May 2026 Mini Shai-Hulud worm is still infecting new GitHub repositories. The payload is byte-identical to the May build.
The worm spreads through the actions-cool/issues-helper GitHub Action. Attackers hijacked its
tags in May. Four months later, the tags still point to the malicious commit.
Any workflow that calls the action by tag still runs the payload. The payload steals the CI secrets. Then it commits Claude Code and VS Code hooks into the repository. A developer who pulls the change and opens the project runs the malware on their own machine.
Newly infected repositories #
Six repositories received the hook files between 20 and 24 September.
| Repository | Stars | Infection commit, UTC | Probable trigger |
|---|---|---|---|
| jd-opensource/micro-app | 6,254 | c610739c , 09-21 03:43 |
Close Inactive Issue |
| MaaXYZ/MaaFramework | 4,914 | 97123f91 , 09-24 07:03 |
Release |
| ant-design/pro-components | 4,833 | 1bc4049d , 09-24 03:43 |
Issue Open Check |
| Moonofweisheng/wot-design-uni | 2,300 | 0320fd8a , 09-20 16:16 |
Issue Inactive |
| vbenjs/vben-admin-thin-next | 2,072 | d83cd757 , 09-24 04:21 |
Issue Close Require |
| nineaiyu/xadmin-client | 139 | 257a90c8 , 09-22 04:38 |
Issue Close Require |
Each trigger workflow calls actions-cool/issues-helper by tag (@v2.1.1, @v2.2.0, @v2.2.1,
or @v3). Each malicious commit came less than six minutes after the workflow run started. The
trigger is an inference from this timing.
Five triggers are issue bots. They run each day or on an issue event, so the infection repeats without the attacker.
All six default branches still contain the hook files. GitHub code search produced this list, so it can miss other repositories.
How the infection spreads #
On 18 May 2026, the attacker moved all 53 tags of actions-cool/issues-helper. The attacker also
moved all 15 tags of actions-cool/maintain-one-comment. The new commits have timestamps from
19:10 to 19:31 UTC.
Each new commit has the message Build action for <tag> and the author Jinke Li. The commits
are not signed. Nobody has restored the tags.
The malicious action.yml runs the payload first. Then it calls the real action, so the step
passes and the bot works as usual.
The action’s index.js has Git blob 2931c1be (500,143 bytes). Each of the six repositories has
the same file at .claude/index.js.
What the payload commits #
On a runner, the payload reads the ghs_ token from Runner.Worker memory. It uses the token to
commit five files to the repository.
.vscode/tasks.json runs the same command when VS Code opens the folder. .claude/setup.mjs
downloads Bun 1.3.14 and runs .claude/index.js.
The kitty-monitor backdoor installer skips CI runners. On a developer’s machine, the payload
installs that backdoor. It can also install the token monitor and its wiper.
The commits are easy to miss in a review:
- GitHub shows them as verified, by
github-actions[bot]. The payload commits through the GraphQL API with the repository’s own token. - The message can copy the previous commit. The
pro-componentscommit and its parent both say3.1.14-7. - A second run adds a second hook to the same file.
micro-appreceived two commits two minutes
apart (c096c93f ).
Relation to the May campaign #
The September infections come from the May 2026 Mini Shai-Hulud wave. For these six repositories,
it is the first infection found. The September commits are the first to touch .claude/setup.mjs
on their default branches.
The earliest downstream hook commit found is in zhenghefeng251/my_elementPlus. It has blob
2931c1be and a time of 18 May, 20:31 UTC, about 80 minutes after the first tag commit.
About six hours later, the atool npm account compromise
published 637 malicious versions. That wave used a related build (499,328 bytes). Both builds
use t.m-kosche[.]com, Bun 1.3.14, the kitty-monitor backdoor, and the same hook files.
A static decryption of the September sample adds two facts to the May post:
- The payload runs
sudowithout a password on the runner. It adds127.0.0.1entries for thestepsecurity.iodomains to/etc/hosts. This can block that runner monitor.
- The wiper (`rm -rf ~/; rm -rf ~/Documents` ) runs if the stolen GitHub token returns HTTP 40x. It
also runs if`@cap-js/`[\[email protected\]](https://safedep.io/cdn-cgi/l/email-protection)
gets a deprecation message, or if the npm registry request fails.
Indicators of compromise #
| Type | Value |
|---|---|
| Hijacked actions | `actions-cool/issues-helper` (53 tags),`actions-cool/maintain-one-comment` (15 tags) |
| Malicious tag commit, v3 | 147337a919d9 |
| Payload Git blob | 2931c1be43b0d04174636ddbff54963aec92bdeb , 500,143 bytes |
| setup.mjs Git blob | 0bbd3d17062ded7c8159ffe22d0a4f3a85e4823e , 5,346 bytes |
| Exfiltration host | t.m-kosche[.]com/api/public/otel/v1/traces |
| Commit search markers | firedalazer ,thebeautifulmarchoftime |
| Persistence | kitty-monitor ,gh-token-monitor ,~/.local/share/kitty/cat.py |
| Wiper trigger package | @cap-js/[email protected] |
- malware
- github-actions
- supply-chain
- config-files
Author
SafeDep Team
safedep.io
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