T1129 — Shared Modules

# T1129 - Shared Modules

## SOC Recommendation
Investigate Shared Modules activity in the context of Execution: confirm scope, affected host/identity, and whether it matches expected administrative behaviour before deciding this is benign.

## D3FEND Mappings
| D3FEND Technique | Relationship | Practical SOC Action |
|---|---|---|
| Network Traffic Analysis | Detect | Monitor for Network Traffic Analysis indicators relevant to this technique. |

## Investigation Steps
1. Review Defender for Endpoint / Defender XDR alerts and timeline for the affected host or identity.
2. Check Sentinel analytics rules and incidents correlated with this technique.
3. Review Entra ID sign-in and audit logs if the technique involves an identity or cloud resource.

## Evidence to Collect
- Host or resource affected
- Account or identity involved
- Timestamp of the activity
- Related process, file, or network artifact
- Any preceding or follow-on alerts

## Response Actions
| Action | Risk | Automation Safe | Approval Required |
|---|---|---|---|
| Contain the affected host or account | Medium | No | Yes |
| Collect and preserve evidence | Low | Yes | No |

## KQL
```kql
DeviceEvents
| where TimeGenerated > ago(24h)
| where ActionType has "<tune to T1129>"
```

## Escalation Criteria
- Shared Modules activity observed on a privileged account or critical system.
- Activity follows or precedes other suspicious behaviour in the same investigation.
- Automated triage cannot confidently rule out malicious intent.

## False Positive Considerations
- Legitimate administrative or maintenance activity matching this pattern.
- Approved security testing or red team exercise.
- Known benign software producing similar telemetry.

Generated by SOC Response Atlas by Basyrix.

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• /api/techniques/T1129.json
• /api/recommendations/T1129.json
• /api/d3fend/T1129.json
• /api/mappings/T1129.json
• /api/confluence/T1129.md

Example curl:

curl https://atlas.basyrix.com/api/recommendations/T1129.json

Response:

{
  "technique_id": "T1129",
  "name": "Shared Modules",
  "priority": "high",
  "status": "draft",
  "version": "0.1.0",
  "last_reviewed": "2026-07-23",
  "generated_by": "SOC Response Atlas by Basyrix",
  "tactics": [
    "Execution"
  ],
  "platforms": [
    "Linux",
    "macOS",
    "Windows"
  ],
  "summary": "Adversaries may execute malicious payloads via loading shared modules. Shared modules are executable files that are loaded into processes to provide access to reusable code, such as specific custom functions or invoking OS API functions (i.e., [Native API](https://attack.mitre.org/techniques/T1106)). Adversaries may use this functionality as a way to execute arbitrary payloads on a victim system...",
  "soc_recommendation": "Investigate Shared Modules activity in the context of Execution: confirm scope, affected host/identity, and whether it matches expected administrative behaviour before deciding this is benign.",
  "d3fend_mappings": [
    {
      "id": "D3-NTA",
      "name": "Network Traffic Analysis",
      "relationship": "detect",
      "practical_action": "Monitor for Network Traffic Analysis indicators relevant to this technique.",
      "tooling": [
        "Sentinel",
        "Defender for Endpoint"
      ]
    }
  ],
  "investigation_steps": {
    "microsoft": [
      "Review Defender for Endpoint / Defender XDR alerts and timeline for the affected host or identity.",
      "Check Sentinel analytics rules and incidents correlated with this technique.",
      "Review Entra ID sign-in and audit logs if the technique involves an identity or cloud resource."
    ],
    "generic": [
      "Confirm whether the observed shared modules activity matches expected administrative or application behaviour.",
      "Identify the host, account, or resource where the activity occurred and its business criticality.",
      "Check for related alerts before and after this activity to reconstruct the broader intrusion timeline.",
      "Real detection reference: \"Suspicious Execution from Foomatic-rip or Cupsd Parent\" -- This detection rule addresses multiple vulnerabilities in the CUPS printing system, including CVE-2024-47176, CVE-2024-47076, CVE-2024-47175, and CVE-2024-47177. Specifically, this rule detects suspicious process command lines executed by child processes of foomatic-rip and cupsd..."
    ]
  },
  "evidence_to_collect": [
    "Host or resource affected",
    "Account or identity involved",
    "Timestamp of the activity",
    "Related process, file, or network artifact",
    "Any preceding or follow-on alerts"
  ],
  "response_actions": [
    {
      "name": "Contain the affected host or account",
      "category": "Containment",
      "risk": "Medium",
      "automation_safe": false,
      "approval_required": true,
      "tool": "Defender for Endpoint / Entra ID",
      "notes": "Requires approval -- confirm malicious intent before isolating a host or disabling an account."
    },
    {
      "name": "Collect and preserve evidence",
      "category": "Investigation",
      "risk": "Low",
      "automation_safe": true,
      "approval_required": false,
      "tool": "Defender for Endpoint",
      "notes": "Safe -- read-only evidence collection."
    }
  ],
  "queries": {
    "kql": [
      {
        "name": "Starting point for T1129",
        "description": "Generic starting query -- tune to the specific data source relevant to this technique.",
        "query": "DeviceEvents\n| where TimeGenerated > ago(24h)\n| where ActionType has \"<tune to T1129>\""
      }
    ],
    "spl": [],
    "esql": [
      {
        "name": "986361cd-3dac-47fe-afa1-5c5dd89f2fb4 — Suspicious Execution from Foomatic-rip or Cupsd Parent",
        "description": "(EQL) This detection rule addresses multiple vulnerabilities in the CUPS printing system, including CVE-2024-47176, CVE-2024-47076, CVE-2024-47175, and CVE-2024-47177. Specifically, this rule detects suspicious process command lines executed by child processes of foomatic-rip and cupsd... (Source: Elastic's official detection-rules repository (Elastic License v2).)",
        "query": "process where host.os.type == \"linux\" and event.type == \"start\" and event.action in (\"exec\", \"exec_event\", \"start\", \"ProcessRollup2\") and\nprocess.parent.name in (\"foomatic-rip\", \"cupsd\") and process.command_line like (\n  // persistence\n  \"*cron*\", \"*/etc/rc.local*\", \"*/dev/tcp/*\", \"*/etc/init.d*\", \"*/etc/update-motd.d*\", \"*/etc/sudoers*\",\n  \"*/etc/profile*\", \"*autostart*\", \"*/etc/ssh*\", \"*/home/*/.ssh/*\", \"*/root/.ssh*\", \"*~/.ssh/*\", \"*udev*\",\n  \"*/etc/shadow*\", \"*/etc/passwd*\",\n\n  // Downloads\n  \"*curl*\", \"*wget*\",\n\n  // encoding and decoding\n  \"*base64 *\", \"*base32 *\", \"*xxd *\", \"*openssl*\",\n\n  // reverse connections\n  \"*GS_ARGS=*\", \"*/dev/tcp*\", \"*/dev/udp/*\", \"*import*pty*spawn*\", \"*import*subprocess*call*\", \"*TCPSocket.new*\",\n  \"*TCPSocket.open*\", \"*io.popen*\", \"*os.execute*\", \"*fsockopen*\", \"*disown*\", \"*nohup*\",\n\n  // SO loads\n  \"*openssl*-engine*.so*\", \"*cdll.LoadLibrary*.so*\", \"*ruby*-e**Fiddle.dlopen*.so*\", \"*Fiddle.dlopen*.so*\",\n  \"*cdll.LoadLibrary*.so*\",\n\n  // misc. suspicious command lines\n   \"*/etc/ld.so*\", \"*/dev/shm/*\", \"*/var/tmp*\", \"*echo*\", \"*>>*\", \"*|*\"\n) and not process.args like \"gs*\""
      },
      {
        "name": "ab9a334a-f2c3-4f49-879f-480de71020d3 — Unusual Library Load via Python",
        "description": "(EQL) Detects when a Python process loads an unusual library from within the user's home directory where the file is not a standard .so or .dylib file. This technique has been observed in APT campaigns by the Lazarus Group and Slow Pisces to load malicious payloads. (Source: Elastic's official detection-rules repository (Elastic License v2).)",
        "query": "library where host.os.type == \"macos\" and event.action == \"load\" and\n  dll.path like \"/Users/*\" and\n  process.name like \"python*\" and\n  not dll.name like (\"*.so\", \"*.dylib\", \"Python\", \"*.*_extension\", \"*.dylib.*\") and\n  not dll.path like (\"*/site-packages/*/Qt*/lib/Qt*.framework/Versions/*/Qt*\",\n                     \"/Users/*/.pyenv/versions/*/lib/python*/site-packages/*\")"
      }
    ]
  },
  "automation": {
    "safe": [
      "Add recommendation as Sentinel incident comment.",
      "Run enrichment queries.",
      "Create ServiceNow SecOps task."
    ],
    "approval_required": [
      "Contain or disable the affected host/account.",
      "Any change to production configuration."
    ]
  },
  "escalation_criteria": [
    "Shared Modules activity observed on a privileged account or critical system.",
    "Activity follows or precedes other suspicious behaviour in the same investigation.",
    "Automated triage cannot confidently rule out malicious intent."
  ],
  "false_positive_considerations": [
    "Legitimate administrative or maintenance activity matching this pattern.",
    "Approved security testing or red team exercise.",
    "Known benign software producing similar telemetry."
  ],
  "confluence": {
    "title": "T1129 - Shared Modules Response Guidance",
    "labels": [
      "mitre",
      "attack",
      "d3fend",
      "secops",
      "basyrix"
    ],
    "sections": [
      "summary",
      "d3fend_mappings",
      "investigation_steps",
      "response_actions",
      "queries",
      "automation",
      "escalation_criteria",
      "false_positive_considerations"
    ]
  }
}