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

Static analysis result for SHA-256 94f1200950488da6…

MALICIOUS

Office (OLE) / .XLSX

440.0 KB
MD5: c0ef43b3d98cb4c429825bd5a7373e07 SHA-1: c99e5c7b7f9f7d00d0566df03512dd5b689ffc3c SHA-256: 94f1200950488da62b802f66d7cca5f274e9de12ae6bece28b5cee57975bccfe
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted Office document containing an Equation Editor OLE object. High-severity heuristics indicate the presence of CVE-2018-0798, a vulnerability in Equation Editor, suggesting it's used for exploitation. The document is encrypted with a default password, a common technique to hide malicious content. No document body or scripts were extractable, but the presence of the Equation Editor exploit is sufficient to infer the attack pattern.

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.