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

Static analysis result for SHA-256 e769e62012f04b8e…

MALICIOUS

Office (OLE) / .XLSX

1.27 MB
MD5: e5c796860be2c013fd0499a3e39d03ba SHA-1: f606f968517cca03df3a352717bbc8db433f9475 SHA-256: e769e62012f04b8e37991da7db96a346347e35b1b2ed4cd84c2a54b32a947af5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking

The sample is an encrypted OOXML file that contains embedded OLE objects, specifically identified as Equation Editor objects. These objects are known exploit carriers, and the presence of an anomalous Ole10Native stream within the Equation Editor object strongly suggests it is designed to deliver a secondary payload. The encryption with a default password further indicates an attempt to obscure the malicious content.

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.