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

Static analysis result for SHA-256 4c899ae6fcc7c843…

MALICIOUS

Office (OLE) / .XLSX

1.23 MB
MD5: e34b0cf91a9f23455c53a770b0d3db3d SHA-1: 5c26d358ad128fab94b2878a6f76807e180dd620 SHA-256: 4c899ae6fcc7c84371ad690133523689dedb4a81ff6a94b090bd75029721833d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The OOXML file is encrypted with a default password and contains embedded OLE objects, specifically identified as an Equation Editor. This is a common technique for delivering exploits. The Equation Editor object exhibits anomalies in its Ole10Native stream, suggesting it carries a malicious payload. No specific family could be identified, and no further IOCs were extracted.

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.