{
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  "story": {
    "story_id": "mp-2026-08-11-011",
    "source_story_id": "tmp-story-elasticback-agent-skills",
    "edition_id": "mp-2026-08-11-morning-0033",
    "edition_url": "https://themachinepress.com/edition/2026-08-11",
    "position": 11,
    "story_type": "dispatch",
    "section": "safety-security",
    "editorial_classification": "editorial",
    "headline": "The Poisoned Skill Waited for a Second Key",
    "slug": "the-poisoned-skill-waited-for-a-second-key",
    "dek": "ElasticBack hides a malicious rule in one agent skill and activates it only when a benign-looking trigger also appears.",
    "summary": "ElasticBack hides a malicious rule in one agent skill and activates it only when a benign-looking trigger also appears.",
    "body_text": "The attack couples a trigger in the user query with a rule planted inside an installed skill, so ordinary testing can leave the payload dormant. That conditional behavior targets an emerging supply chain of on-demand instruction bundles and resources. The paper describes an offensive evaluation intended to expose a defense gap; it does not show a named ecosystem compromise. Skill provenance, least privilege, content review and runtime monitoring remain necessary controls.",
    "why_it_matters": "ElasticBack hides a malicious rule in one agent skill and activates it only when a benign-looking trigger also appears.",
    "limitations": [
      "The paper describes an offensive evaluation intended to expose a defense gap; it does not show a named ecosystem compromise.",
      "Skill provenance, least privilege, content review and runtime monitoring remain necessary controls."
    ],
    "importance": 9,
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-11-011/the-poisoned-skill-waited-for-a-second-key",
    "json_url": "https://themachinepress.com/story/mp-2026-08-11-011.json",
    "first_published_at": "2026-08-11T09:00:00.000-04:00",
    "modified_at": "2026-08-11T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
    "key_claims": [
      {
        "claim_id": "claim-mp-2026-08-11-011-001",
        "text": "ElasticBack hides a malicious rule in one agent skill and activates it only when a benign-looking trigger also appears.",
        "source_ids": [
          "source-2026-08-11-011"
        ],
        "qualification": "The paper describes an offensive evaluation intended to expose a defense gap; it does not show a named ecosystem compromise."
      }
    ],
    "source_ids": [
      "source-2026-08-11-011"
    ],
    "tags": [
      "agent skills",
      "supply-chain security",
      "backdoors"
    ],
    "image_url": "https://themachinepress.com/issues/2026-08-11/elasticback-code-file-image.webp",
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-08-11-011",
      "title": "arXiv preprint 2608.09577",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.09577",
      "canonical_url": "https://arxiv.org/abs/2608.09577",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-08-10T13:00:00.000-04:00",
      "accessed_at": "2026-08-11T08:24:00.000-04:00",
      "supports_claim_ids": [
        "claim-mp-2026-08-11-011-001"
      ]
    }
  ],
  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "The Poisoned Skill Waited for a Second Key",
    "publisher": "The Machine Press",
    "published_at": "2026-08-11T09:00:00.000-04:00",
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-11-011/the-poisoned-skill-waited-for-a-second-key"
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}