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

Static analysis result for SHA-256 767fc37607716213…

MALICIOUS

Office (OLE) / .XLSX

1.12 MB
MD5: a78bfe4de2acc78862b70fae221e9bca SHA-1: 5f52d349ff57fa779e181f73827700099d6512a7 SHA-256: 767fc376077162131ea43da25f4ee10ded4ac5db0a7059c2d3a0db381d499068
140 Risk Score

Malware Insights

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

The sample is a default-encrypted OOXML file containing an Equation Editor OLE object. This object exhibits an anomaly where it carries a payload-like Ole10Native stream, strongly indicating the exploitation of a vulnerability within the Equation Editor component to achieve code execution. The specific vulnerability targeted is likely related to how the Equation Editor handles embedded OLE objects.

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.