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

Static analysis result for SHA-256 8f8f5bf3c44375eb…

MALICIOUS

Office (OLE) / .XLSX

510.5 KB
MD5: 85c3a967a99d6c181ec434836f6731de SHA-1: b2a176e57a8de0bd7477c229e3394a08b84c582c SHA-256: 8f8f5bf3c44375eb2f9fd15dbe8c470f0bd71096a3204e1a6dea42d054d52090
120 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The sample is a password-encrypted Office document. Heuristics indicate it contains an Equation Editor OLE object, a common carrier for exploits like CVE-2017-11882. The encryption prevents further static analysis of the document body or embedded scripts, but the presence of the Equation Editor OLE object strongly suggests an exploit delivery mechanism.

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.
  • Office document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.