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

Static analysis result for SHA-256 cf1ac3dc47fa4db6…

MALICIOUS

Office (OLE) / .XLSX

651.0 KB
MD5: afa634db11052e5a98096e22314bcff6 SHA-1: 7bb72809de258f7b3bf548f537ed817daa389220 SHA-256: cf1ac3dc47fa4db604ca8081401d60b1d8528bac57d34ee894a35cf529c3a664
120 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The sample is a password-encrypted Office document, a common technique for obfuscating malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object, a known vector for exploiting vulnerabilities like CVE-2017-11882. The encryption and exploit carrier structure suggest it's designed to deliver a secondary payload.

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.