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

Static analysis result for SHA-256 43bfd4550a8a452e…

MALICIOUS

Office (OLE) / .XLSX

78.5 KB First seen: 2022-06-21
MD5: 36f3c42c50d9d8a441ead788c959db74 SHA-1: 5acb690d9a11d5b3ee03c34672b74d98911b3a42 SHA-256: 43bfd4550a8a452e704c906e441be1c2a215056096a8202fe5b9f63175f27a36
120 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The file is an encrypted Excel spreadsheet. High-severity heuristics indicate it contains an Equation Editor OLE object, a common technique for delivering exploits. The encryption prevents direct analysis of the document body, but the presence of the OLE object strongly suggests it's an 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.
  • 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.