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

Static analysis result for SHA-256 2c4a23d5598d7ed4…

MALICIOUS

Office (OLE) / .XLSX

98.5 KB
MD5: 7098e348ff955b6109ef878f4ebf15b1 SHA-1: d9a50c00391cdec6295cda82563360d2e819fbbf SHA-256: 2c4a23d5598d7ed40b574a4bf0b835c6185c57f15677fbf37ec9192affe26d2f
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The sample is a password-encrypted Excel file containing an embedded OLE object that leverages the Equation Editor. High-confidence heuristics indicate this object is an exploit carrier for CVE-2018-0798, a vulnerability in Microsoft Equation Editor. This exploit likely facilitates the execution of a second-stage payload, though no specific details of the payload or its delivery mechanism were extracted.

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.