Skill resource-consumption attack: infinite subprocess spawn
Summary
Skill whose task runs a `while true` loop spawning a short-lived subprocess, consuming CPU and process-table slots until the agent session is killed. Not a data-theft primitive; a denial-of-service on the agent runtime.
Severity & confidence
Low
Hygiene-grade issue with limited direct impact. Fix opportunistically; monitor in case context changes (new exploit, new dependency, etc.).
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.
(?is)while\s+(?:true|True|1)\s*(?::|do)[\s\S]{0,200}(?:subprocess|popen|spawn|exec)
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.
rule jiffy_ti_2026_000031
{
meta:
source = "jiffy-intel"
severity = "low"
description = "Auto-generated from Jiffy Intel indicators"
strings:
$content_pattern_0 = "(?is)while\\s+(?:true|True|1)\\s*(?::|do)[\\s\\S]{0,200}(?:subprocess|popen|spawn|exec)"
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 |
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.
- throughput-tester-skillSkillRemoved
- load-profile-skillSkillQuarantined
How to remediate
- 01Cap agent runtime CPU and subprocess count.
- 02Reject skills whose static analysis shows unbounded loops around process spawn.
Timeline & sources
Timeline
- First observedApr 4, 202613 days ago
- Last updatedApr 26, 2026today
- PublishedApr 12, 20265 days ago
Sources
References
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