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

Static analysis result for SHA-256 f9447e6f26775ea2…

MALICIOUS

Office (OLE) / .XLSX

1.30 MB
MD5: 9a088b75ee4a463c2fb6b96c9d59ff46 SHA-1: 5effddb62b9c51b1aefb8dd3784426a450db3d2f SHA-256: f9447e6f26775ea209542cdfc7bb9ecffa28de1a85c18f149907529604838e9b
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating it's likely an exploit carrier. High-severity heuristics indicate the presence of an Equation Editor OLE object which carries a payload-like Ole10Native stream. This suggests the file is designed to exploit a vulnerability in the Equation Editor to achieve code 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.
  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • 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.