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

Static analysis result for SHA-256 d91d8f9db57391c7…

MALICIOUS

Office (OLE) / .XLSX

317.5 KB
MD5: c10c2ac9748bc7715e93561e22137915 SHA-1: 7d754dca604b622b4d2d9ca001ff17eec5d6542e SHA-256: d91d8f9db57391c71c4dee95dfdc6ec3a6466703ae8cf9f011259d3948bc8728
160 Risk Score

Malware Insights

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

The file is a password-encrypted OOXML document containing an embedded Equation Editor OLE object. High-confidence heuristics indicate this object is an exploit carrier for CVE-2018-0798, characterized by an anomalous native stream. This suggests the document is designed to exploit this vulnerability upon opening, likely leading to the execution of a secondary payload.

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.