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

Static analysis result for SHA-256 e1d933814ae5c1a3…

MALICIOUS

Office (OLE) / .XLSX

369.5 KB
MD5: 933eacdc505cb6cde8cfa43619b6d6a3 SHA-1: d85efc772145b6ffd55ef55c9f78ecc1cee6c6ed SHA-256: e1d933814ae5c1a37e6753eb43ac9a80901e9b1a9b120af3bebea4619f34d987
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. Heuristics indicate exploitation of CVE-2018-0798 via anomalous Equation Editor native stream, suggesting it's an exploit carrier. No document body or scripts were extractable due to encryption, but the presence of the Equation Editor exploit is a strong indicator of malicious intent.

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.