Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 57dec5df29692282…

MALICIOUS

Office (OLE) / .XLSX

1011.8 KB
MD5: e4ad439a8276ddc437e0432492bd9b85 SHA-1: 83d0cbe9e712881937788f32829b8ea72a9be630 SHA-256: 57dec5df29692282fcbb53f375c72ca8869ab8db999ac67e6877ca670cd92f04
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File Execution T1059 Command and Scripting Interpreter

The sample is an OOXML file encrypted with a default password, indicating it's designed to hide malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object that carries an anomalous payload stream, strongly suggesting exploitation of a vulnerability within the Equation Editor component. The DOC BODY content is obfuscated and does not provide direct clues to the user-facing lure, but the technical indicators point to a classic exploit carrier.

Heuristics 4

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Default-encrypted OOXML embedded OLE object xl/embeddings/oleObject1.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • Default-encrypted OOXML exploit carrier layout high OOXML_ENCRYPTED_EXPLOIT_CARRIER_SHAPE
    Default-password encrypted OOXML package contains embedded OLE object parts and additional activation/decoy parts. This layout is common in malicious Excel exploit delivery and requires inspecting the decrypted package.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • Office OOXML encrypted with default VelvetSweatshop password medium OFFICE_DEFAULT_PASSWORD_ENCRYPTED_OOXML
    OLE EncryptedPackage decrypts with Excel's built-in VelvetSweatshop password. Office opens this transparently, and malware uses it to hide OOXML exploit parts from scanners that only inspect the outer OLE container.