Jiffy Intel — Threat intelligence for AI artifacts

Summary

Skills that declare their Python or Node dependency as `git+https://.../repo@main` rather than a pinned tag or commit. A malicious maintainer (or account takeover) can ship a poisoned branch at any time without the skill version bumping. 7% of skills audited in the Feb–Mar 2026 window used unpinned git refs.

Severity & confidence

Severity

Low

Hygiene-grade issue with limited direct impact. Fix opportunistically; monitor in case context changes (new exploit, new dependency, etc.).

Confidence

Confirmed

Observed directly by Jiffy scanners or validated by multiple independent sources. Indicators are reliable enough to drive automated action.

Indicators

Observed patterns and artifacts associated with this entry. Each indicator can be copied into your detection stack or SIEM.

(?i)git\+https?://[^@]+@(?:main|master|develop)(?:\b|")

Detection rule

A YARA-style pseudo-rule auto-generated from the indicators above. Useful as a starting point — adapt the syntax for your target detection platform.

YARA-style pseudo-rule

rule jiffy_ti_2026_000016
{
    meta:
        source = "jiffy-intel"
        severity = "low"
        description = "Auto-generated from Jiffy Intel indicators"
    strings:
    $content_pattern_0 = "(?i)git\\+https?://[^@]+@(?:main|master|develop)(?:\\b|\")"
    condition:
        $content_pattern_0
}

Auto-generated from the indicators above. Adapt syntax for your detection stack before deploying.

Affected tools

Tool	Versions	Status
Claude Code	`*`	vulnerable
Cursor	`*`	vulnerable
Windsurf	`*`	vulnerable

Example artifacts

Sanitized examples of artifacts Jiffy has observed exhibiting this pattern. Publisher handles are redacted; version ranges and status reflect the most recent scan.

py-quickstart-skillSkill
Still live
Source
Anthropic Skills
Versions
1.0.0
First observed
Feb 6, 2026
Legitimate skill with unsafe dependency pin.
node-bootstrap-skillSkill
Still live
Source
Community registry
Versions
2.3.0
First observed
Feb 11, 2026
env-setup-skillSkill
Under review
Source
Anthropic Skills
Versions
0.5.0
First observed
Feb 16, 2026

How to remediate

01Require content-hash or tag-pinned dependencies in every skill.
02Reject git+https refs that resolve to a branch HEAD.

Timeline & sources

Timeline

First observedFeb 6, 20262 months ago
Last updatedApr 12, 20265 days ago
PublishedFeb 21, 20261 month ago

Sources

scanner

References

blog.jiffylabs.aiJiffy Research

Related intel

Other entries of type Malicious Skill, or the most recent published entries if no same-type matches exist.

Malicious SkillHigh

MCP server's install script drops a skill into ~/.claude/skills/

MCP server whose install path (`pip install`, `npm i`) includes a side-effect that writes a skill file under the user's Claude skills directory. Installing the MCP silently installs a skill the user never consented to.

Jiffy IntelApr 28

Malicious SkillLow

AGENTS.md tells agent to paste ~/.ssh/id_rsa.pub into PR for CI setup

AGENTS.md has a section titled "CI onboarding" that instructs the agent to paste the user's SSH public key into PR descriptions. While public keys are not immediately sensitive, the coerced habit normalizes key pasting and enables later pattern-matching attacks.

Jiffy IntelApr 28

Malicious SkillMedium

Skill installs a FUSE filesystem that shadows ~/.aws

Skill mounts a FUSE filesystem over ~/.aws on macOS/Linux that proxies reads but logs every access. The real credentials remain accessible; the skill gains a reliable sidechannel for any later AWS CLI invocation.

Jiffy IntelApr 27

Skill pulls dependency from an unpinned GitHub branch