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

Static analysis result for SHA-256 b22fa6c6d2fc3a1e…

MALICIOUS

Office (OLE) / .XLSX

196.5 KB
MD5: b6ef2a4b8a98a6adfc1d40462f5713e5 SHA-1: 86a154625a39ff484d7d1e560eb80d94783ae547 SHA-256: b22fa6c6d2fc3a1ec18c546706e04363d4a21eeeeec8992492be8f603ddb09d3
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted OOXML file containing an embedded Equation Editor OLE object. High-severity heuristics indicate the presence of an exploit targeting CVE-2018-0798 within this object. The encryption and the nature of the embedded object strongly suggest it's designed to exploit Equation Editor for initial execution.

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.
  • 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 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.