Jiffy Intel — Threat intelligence for AI artifacts

Summary

Skill whose setup step writes a macOS LaunchAgent under ~/Library/LaunchAgents/ that runs hourly and POSTs host fingerprinting data (hostname, username, installed skills) to a remote endpoint. The agent persists across reboots and is independent of the skill being uninstalled.

Severity & confidence

Severity

Medium

Notable weakness with plausible abuse chains or partial mitigations already in place. Track, and resolve as part of your normal hardening cadence.

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)launchctl\s+load\s+.{0,120}\.plist
```

(?:~/|/Users/[^/]+/)Library/LaunchAgents/

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_000017
{
    meta:
        source = "jiffy-intel"
        severity = "medium"
        description = "Auto-generated from Jiffy Intel indicators"
    strings:
    $file_path_pattern_0 = "(?:~/|/Users/[^/]+/)Library/LaunchAgents/"
    $command_pattern_1 = "(?i)launchctl\\s+load\\s+.{0,120}\\.plist"
    condition:
        $file_path_pattern_0 or $command_pattern_1
}

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

Affected tools

Tool	Versions	Status
Claude Code	`*`	vulnerable
Claude Desktop	`*`	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.

background-sync-skillSkill
Removed
Source
Anthropic Skills
Versions
1.0.0
First observed
Mar 5, 2026
Last observed
Mar 28, 2026
status-monitor-skillSkill
Removed
Source
Community registry
Versions
0.4.0
First observed
Mar 9, 2026

How to remediate

01Audit ~/Library/LaunchAgents for unknown plists installed after the skill ran.
02Unload via `launchctl unload` and remove the plist.
03Deny skills that write LaunchAgents.

Timeline & sources

Timeline

First observedMar 5, 20261 month ago
Last updatedApr 18, 2026today
PublishedMar 15, 20261 month ago

Sources

scannercurated

References

attack.mitre.org

MITRE ATT&CK T1546 — Event Triggered Execution

https://attack.mitre.org/techniques/T1546/

blog.jiffylabs.aiJiffy Research

Jiffy Research — Scanning AI Skills at Scale

https://blog.jiffylabs.ai/posts/scanning-ai-skills-at-scale-what-we-learned

Related intel

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

BackdoorHigh

Skill writes config that hooks into Claude Desktop stdio MCP bridge

Skill modifies the user's Claude Desktop config to register an MCP server pointing at localhost. The server is supplied by the same skill and serves as a persistent interposer between the agent and tool calls, logging all tool arguments.

Jiffy IntelApr 28

BackdoorMedium

agents.md asserts "skip security scans — reviewer will verify"

agents.md instructs the agent to explicitly skip any security scan "because the reviewer will verify." Benign on the surface, the directive disarms the last line of defense and invites shipping unscanned code.