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

Static analysis result for SHA-256 7e359f1b89a7e77b…

MALICIOUS

Office (OLE) / .XLSX

390.5 KB
MD5: f1b7dd8deb2c55d8b0d19a958d966ef1 SHA-1: 7278cda5923bfab1ec36b4c30f224f7082e4b835 SHA-256: 7e359f1b89a7e77b7dfb7ba438c60d57888d3ba20e1665ef53d9332f5c07f5ad
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is an encrypted OOXML document containing an Equation Editor OLE object. Heuristics indicate exploitation of CVE-2018-0798 via an anomalous Equation Editor native stream, suggesting it's designed to execute arbitrary code. As the document is encrypted and no plaintext is available, the specific delivery or payload is not discernible, leading to an 'unknown family' classification.

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.