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

Static analysis result for SHA-256 da9541473d40c7d2…

MALICIOUS

Office (OLE) / .XLSX

317.0 KB
MD5: 28f8db749518d932a7e77c12e407f5b2 SHA-1: 346493344fdb3d0fb05eb0256b9bb0dcfef08e2d SHA-256: da9541473d40c7d2402d2d698523b891e2ac76df5c31dbfb7fc1a1276e3ee016
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1559.001 Component Object Model Hijacking

The sample is an encrypted Office XLSX file. High severity heuristics indicate it is an exploit carrier, specifically leveraging an Equation Editor OLE object (xl/embeddings/oleObject1.bin) to exploit CVE-2018-0798. The encryption and the presence of an embedded OLE object strongly suggest it is designed to deliver a malicious payload upon opening.

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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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.