{
  "Event": {
    "analysis": "1",
    "date": "2026-06-03",
    "extends_uuid": "",
    "info": "[Threat Intel] From Malspam to Fileless .NET Loader",
    "protected": false,
    "publish_timestamp": "1781559735",
    "published": true,
    "threat_level_id": "2",
    "timestamp": "1781559734",
    "uuid": "10570b78-9ce0-4a79-a52d-7da02fd487ca",
    "Orgc": {
      "name": "Rectifyq",
      "uuid": "cd9bd516-61fa-476b-980f-2f8de03992d4"
    },
    "Tag": [
      {
        "colour": "#8f20d0",
        "local": false,
        "name": "misp-galaxy:producer=\"Huntress\"",
        "relationship_type": ""
      },
      {
        "colour": "#ffffff",
        "local": false,
        "name": "tlp:clear",
        "relationship_type": ""
      },
      {
        "colour": "#004646",
        "local": false,
        "name": "type:OSINT",
        "relationship_type": ""
      },
      {
        "colour": "#b94b1d",
        "local": false,
        "name": "rectifyq:mitre-att&ck=\"none-from-src\"",
        "relationship_type": ""
      },
      {
        "colour": "#b94b1d",
        "local": false,
        "name": "rectifyq:mitre-att&ck=\"from-OTX\"",
        "relationship_type": ""
      },
      {
        "colour": "#705cef",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Scheduled Task - T1053.005\"",
        "relationship_type": ""
      },
      {
        "colour": "#47d9d3",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Malicious File - T1204.002\"",
        "relationship_type": ""
      },
      {
        "colour": "#56c932",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Symmetric Cryptography - T1573.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#2c1d2e",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"System Checks - T1497.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#51b040",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"InstallUtil - T1218.004\"",
        "relationship_type": ""
      },
      {
        "colour": "#5539fe",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Spearphishing Attachment - T1566.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#7d7034",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"System Information Discovery - T1082\"",
        "relationship_type": ""
      },
      {
        "colour": "#a92e1c",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Deobfuscate/Decode Files or Information - T1140\"",
        "relationship_type": ""
      },
      {
        "colour": "#f4b62b",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Time Based Checks - T1497.003\"",
        "relationship_type": ""
      },
      {
        "colour": "#3b96ed",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"CMSTP - T1218.003\"",
        "relationship_type": ""
      },
      {
        "colour": "#bf01b7",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Modify Registry - T1112\"",
        "relationship_type": ""
      },
      {
        "colour": "#461928",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Indicator Blocking - T1562.006\"",
        "relationship_type": ""
      },
      {
        "colour": "#755c09",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"PowerShell - T1059.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#b76d96",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Registry Run Keys / Startup Folder - T1547.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#e43954",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Disable or Modify Tools - T1562.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#4bc785",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Process Hollowing - T1055.012\"",
        "relationship_type": ""
      },
      {
        "colour": "#e08bb2",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Obfuscated Files or Information - T1027\"",
        "relationship_type": ""
      },
      {
        "colour": "#30cc3b",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"File Deletion - T1070.004\"",
        "relationship_type": ""
      },
      {
        "colour": "#92e858",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Web Protocols - T1071.001\"",
        "relationship_type": ""
      },
      {
        "colour": "#98f3da",
        "local": false,
        "name": "misp-galaxy:mitre-attack-pattern=\"Visual Basic - T1059.005\"",
        "relationship_type": ""
      },
      {
        "colour": "#49a260",
        "local": false,
        "name": "rectifyq:category=\"threat\"",
        "relationship_type": ""
      },
      {
        "colour": "#120044",
        "local": false,
        "name": "rectifyq:sub-category=\"intrusion-analysis\"",
        "relationship_type": ""
      },
      {
        "colour": "#d92121",
        "local": false,
        "name": "rectifyq:target=\"targeted\"",
        "relationship_type": ""
      },
      {
        "colour": "#55acee",
        "local": false,
        "name": "rectifyq:MY-relevancy=\"potentially-relevant\"",
        "relationship_type": ""
      },
      {
        "colour": "#626567",
        "local": false,
        "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
        "relationship_type": ""
      },
      {
        "colour": "#626567",
        "local": false,
        "name": "rectifyq:no-samples-in=\"Tria.ge\"",
        "relationship_type": ""
      },
      {
        "colour": "#3800d9",
        "local": false,
        "name": "rectifyq:action-taken=\"VT-comment\"",
        "relationship_type": ""
      },
      {
        "colour": "#3d00e9",
        "local": false,
        "name": "rectifyq:action-taken=\"telegram\"",
        "relationship_type": ""
      }
    ],
    "Attribute": [
      {
        "category": "External analysis",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781089220",
        "to_ids": false,
        "type": "link",
        "uuid": "01f09f1f-e55b-481d-8e68-b5344783c31c",
        "value": "https://www.huntress.com/blog/malspam-to-loader-delivery-chain-analysis"
      },
      {
        "category": "Other",
        "comment": "Description",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781089220",
        "to_ids": false,
        "type": "text",
        "uuid": "b2d95abb-34bb-4c94-8b41-89e5e9424570",
        "value": "A sophisticated malspam campaign delivers a multi-stage .NET loader through an elaborate chain beginning with HTML email attachments. The attack routes through legitimate Google DoubleClick infrastructure to evade detection, then deploys a dynamically personalized phishing kit that pulls victim company branding in real-time. The infection chain progresses through JavaScript, PowerShell, and multiple .NET components, executing primarily in-memory while actively patching AMSI and ETW to blind Windows telemetry. The loader performs extensive anti-analysis checks, terminates or reboots upon detecting sandboxes or debugging tools, and establishes persistence through registry keys and scheduled tasks disguised as NVIDIA components. It targets Microsoft-signed binaries like InstallUtil.exe and MSBuild.exe for process injection, maintains C2 communications over non-standard ports using AES-encrypted protobuf messages, and profiles victim systems including specific GPU enumeration potentially for cryptocurrency min..."
      },
      {
        "category": "Other",
        "comment": "Summary",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781089220",
        "to_ids": false,
        "type": "text",
        "uuid": "e3824f71-ae74-45ef-8ea6-c10c65a08313",
        "value": "Name: From Malspam to Fileless .NET Loader\nAuthor: AlienVault\nAdversary: \nTags: [\"malspam\", \"sandbox detection\", \"ddns c2\", \"fileless\", \"amsi patching\"]\nTgtd countries: []\nMlwr families: []\nAttack_ids: [\"T1053.005\", \"T1204.002\", \"T1573.001\", \"T1497.001\", \"T1218.004\", \"T1566.001\", \"T1082\", \"T1140\", \"T1497.003\", \"T1218.003\", \"T1112\", \"T1562.006\", \"T1059.001\", \"T1547.001\", \"T1562.001\", \"T1055.012\", \"T1027\", \"T1070.004\", \"T1071.001\", \"T1059.005\"]\nIndustries: []"
      },
      {
        "category": "External analysis",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781089220",
        "to_ids": false,
        "type": "vulnerability",
        "uuid": "ef40147b-472d-4b7f-b914-ecc7b8cdffdf",
        "value": "CVE-2023-46604"
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435552",
        "to_ids": true,
        "type": "hostname",
        "uuid": "8f8b8929-ce3f-4175-964c-b56d29251488",
        "value": "xtadts.ddns.net",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435573",
        "to_ids": true,
        "type": "hostname",
        "uuid": "7a879591-ee57-4d09-a373-9409cd0dd452",
        "value": "afxwd.ddns.net",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "Serves bl.txt (the packed loader), payload delivery",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435594",
        "to_ids": true,
        "type": "hostname",
        "uuid": "17f05051-b211-4d99-a908-71bbd4ec97b3",
        "value": "catalogo.castrouria.com",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Payload delivery",
        "comment": "Loader's hardcoded C2 certificate pin No sample in VT\r\nLast check:14/06/2026",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781434306",
        "to_ids": true,
        "type": "sha256",
        "uuid": "0e2cbd33-6fb7-4a3a-a68b-039919019cb7",
        "value": "c356aff1a01c2b0da472e584c8e3c8f875b9a24280435d42836a77b19f5a8c18",
        "Tag": [
          {
            "colour": "#260091",
            "local": false,
            "name": "rectifyq:ioc=\"enriched\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"VirusTotal\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"Tria.ge\"",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Payload delivery",
        "comment": "Loader's hardcoded C2 certificate pin No sample in VT\r\nLast check:14/06/2026",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781434307",
        "to_ids": true,
        "type": "sha256",
        "uuid": "75983a87-7bbf-458c-b6d1-0f7052f5b268",
        "value": "c61b1941cf756eb7551f7c661743802362728b785adc22e860d269713dfb01a6",
        "Tag": [
          {
            "colour": "#260091",
            "local": false,
            "name": "rectifyq:ioc=\"enriched\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"VirusTotal\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"Tria.ge\"",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Payload delivery",
        "comment": "Loader's hardcoded C2 certificate pin No sample in VT\r\nLast check:14/06/2026",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781434308",
        "to_ids": true,
        "type": "sha256",
        "uuid": "9a4db78e-e62b-45f6-89cf-f6102afce4f4",
        "value": "d5b7247c497788cf0031ceb06e3df77a45fef59f1e49633dc7159816d64759b5",
        "Tag": [
          {
            "colour": "#260091",
            "local": false,
            "name": "rectifyq:ioc=\"enriched\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"VirusTotal\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"Tria.ge\"",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Payload delivery",
        "comment": "Loader's hardcoded C2 certificate pin No sample in VT\r\nLast check:14/06/2026",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781434309",
        "to_ids": true,
        "type": "sha256",
        "uuid": "dc3d0950-aef2-4adc-ae28-af93998e2ff0",
        "value": "f1c3ebe78bd8c38559bf3cfcc9a9fa37d221e31780774a3787e26160a61f5348",
        "Tag": [
          {
            "colour": "#260091",
            "local": false,
            "name": "rectifyq:ioc=\"enriched\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"VirusTotal\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"Tria.ge\"",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "Redirector stage",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435615",
        "to_ids": true,
        "type": "hostname",
        "uuid": "28b9573f-7345-4b47-9fbc-b1ac929042de",
        "value": "fostercareintheus.optimizationprime.com",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Payload delivery",
        "comment": "Loader's hardcoded C2 certificate pin No sample in VT\r\nLast check:14/06/2026",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781434310",
        "to_ids": true,
        "type": "sha256",
        "uuid": "22785c3d-504d-401f-9de1-580aa75e9be5",
        "value": "e91fb249aa97be5c7931e430781167edfe7ba804720b5f643e6ab70b7e6e74dd",
        "Tag": [
          {
            "colour": "#260091",
            "local": false,
            "name": "rectifyq:ioc=\"enriched\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"VirusTotal\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"MalwareBazaar\"",
            "relationship_type": ""
          },
          {
            "colour": "#626567",
            "local": false,
            "name": "rectifyq:no-samples-in=\"Tria.ge\"",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435636",
        "to_ids": true,
        "type": "url",
        "uuid": "bab643dc-4f83-4e89-aef0-3356f946137d",
        "value": "http://catalogo.castrouria.com/c84da/bl.txt",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "This serves the ZIP archive it's payload delivery",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435657",
        "to_ids": true,
        "type": "url",
        "uuid": "53fbc3ac-ba1f-48ef-a97d-df51c482c45d",
        "value": "http://pengajian.muliastudy.com/images/edu/u.php",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435679",
        "to_ids": true,
        "type": "url",
        "uuid": "a3c4cd1c-982e-4e4a-b4d4-0f9fec1ae41a",
        "value": "https://andrefelipedonascime1778799406970.2241107.meusitehostgator.com.br/GpazlLUWIJ_14_05_Meus_ArquivosDeTexto/02.txt",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435700",
        "to_ids": true,
        "type": "url",
        "uuid": "f052ee30-9769-4c9e-808c-a64fa7d7619f",
        "value": "https://pengajian.muliastudy.com/images/edu/u.php",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435721",
        "to_ids": true,
        "type": "hostname",
        "uuid": "6ccbe829-e0bf-43d9-8b77-bdc8935c5b7f",
        "value": "andrefelipedonascime1778799406970.2241107.meusitehostgator.com.br",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435742",
        "to_ids": true,
        "type": "hostname",
        "uuid": "dfac1245-28ee-4f12-9fa7-66887ee11d4f",
        "value": "bth.startthewave.org",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "This serves the ZIP archive it's payload delivery",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435763",
        "to_ids": true,
        "type": "hostname",
        "uuid": "2bd64d28-0121-4585-a792-abb525fe130b",
        "value": "pengajian.muliastudy.com",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435784",
        "to_ids": true,
        "type": "url",
        "uuid": "125468dd-3eea-45fc-8f00-4aeaaed7f98c",
        "value": "pengajian.muliastudy.com/images/edu/u.php",
        "Tag": [
          {
            "colour": "#f08989",
            "local": false,
            "name": "NotFoundError",
            "relationship_type": ""
          }
        ]
      },
      {
        "category": "Network activity",
        "comment": "",
        "deleted": false,
        "disable_correlation": false,
        "timestamp": "1781435805",
        "to_ids": true,
        "type": "domain",
        "uuid": "01d90f2a-e513-4e5b-940f-75e85229bb67",
        "value": "a021185521s210008-11521.zip",
        "Tag": [
          {
            "colour": "#342294",
            "local": false,
            "name": "CommentAdded",
            "relationship_type": ""
          }
        ]
      }
    ]
  }
}