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

Static analysis result for SHA-256 b8d34b3c639a5ac1…

MALICIOUS

Office (OLE) / .XLSX

1.27 MB
MD5: 8e199f584a4181060174f2be93d9aedd SHA-1: cbe76952530ae32250209e8b0532759bf06743bc SHA-256: b8d34b3c639a5ac13c53961eb920ca3e25ca0b038552802984bb41a98a02c08f
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 that is encrypted with a default password and contains an Equation Editor OLE object. This object exhibits an anomaly where it carries a payload-like Ole10Native stream, indicating it's likely an exploit carrier. The presence of the Equation Editor OLE object strongly suggests exploitation of a vulnerability within it 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.