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

Static analysis result for SHA-256 167ab795206ab852…

MALICIOUS

Office (OLE) / .XLSX

1.26 MB
MD5: 27063cb28a2ae38c36f6534bf83f1b05 SHA-1: 0b837c582682704741d565eb8e68d8dc29ace8f0 SHA-256: 167ab795206ab85259affeff91f06bf6c4ac2b617a35bc00fdfd0cb9294dca3f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a password-encrypted Office document containing an embedded Equation Editor OLE object, a known carrier for exploits. The encryption and malformed structure indicate an attempt to obfuscate malicious content. The presence of the Equation Editor OLE object strongly suggests exploitation for client execution, likely delivered via spearphishing.

Heuristics 5

  • 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.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • 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)).
  • 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.