A Sigma rule object contains a Sigma rule used during a Sigma Analysis. For more information check the Sigma wiki. It contains the following attributes:

description: <string>: brief description about what the rule is detecting.
detections: <dictionary> defines detection patterns and conditions.
false_positives: <list of strings>: list of known false positives.
fields: <list of strings>: fields that are helpful in the evaluation of a certain event.
level: <string> can be either "low", "medium", "high" or "critical".
log_source: <string> rule's log source.
references: <list of strings>: external links to get more context about what is the rule detecting.
source: <string> ruleset source.
status: <string>: can be either "experimental" for new rules or "stable" for rules that have been running in production for a couple of months.
tags: <string> rule tags.
title: <string> rule title.

{
  "data": {
    "attributes": {
      "description": "<string>",
      "detection": {
        "condition": "<string>",
        "details": {
          "<string>": "<string>"
        }
      },
      "false_positives": [
        "<string>"
      ],
      "fields": [
        "<string>"
      ],
      "level": "<string>",
      "log_source": {
        "category": "<string>",
        "definition": "<string>",
        "product": "<string>",
        "service": "<string>"
      },
      "references": [
        "<string>"
      ],
      "source": "<string>",
      "status": "<string>",
      "tags": [
        "<string>"
      ],
      "title": "<string>"
    },
    "id": "<string>",
    "links": {
      "self": "https://www.virustotal.com/api/v3/sigma_rules/<id>"
    },
    "type": "sigma_rule"
  }
}

{
  "data": {
    "attributes": {
      "description": "Detects usage of attrib.exe to hide files from users.",
      "detection": {
        "condition": "selection and not (ini or intel)",
        "details": {
          "ini": "{\"CommandLine\":\"*\\\\desktop.ini *\"}",
          "intel": "{\"CommandLine\":\"+R +H +S +A \\\\\\\\*.cui\",\"ParentCommandLine\":\"C:\\\\WINDOWS\\\\system32\\\\\\\\*.bat\",\"ParentImage\":\"*\\\\cmd.exe\"}",
          "selection": "{\"CommandLine\":\"* +h *\",\"Image\":\"*\\\\attrib.exe\"}"
        }
      },
      "false_positives": [
        "igfxCUIService.exe hiding *.cui files via .bat script (attrib.exe a child of cmd.exe and igfxCUIService.exe is the parent of the cmd.exe)",
        "msiexec.exe hiding desktop.ini"
      ],
      "fields": [
        "CommandLine",
        "ParentCommandLine",
        "User"
      ],
      "level": "low",
      "log_source": {
        "category": "process_creation",
        "definition": "",
        "product": "windows",
        "service": ""
      },
      "references": [],
      "source": "Sigma Integrated Rule Set (GitHub)",
      "status": "experimental",
      "tags": [],
      "title": "Hiding Files with Attrib.exe"
    },
    "id": "5c3ea6806114163b8cdf5735aeb07e702ab63e0e486f721df84cf675e2b0a04b",
    "links": {
      "self": "https://www.virustotal.com/api/v3/sigma_rules/5c3ea6806114163b8cdf5735aeb07e702ab63e0e486f721df84cf675e2b0a04b"
    },
    "type": "sigma_rule"
  }
}