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

Static analysis result for SHA-256 e8ef77f22c8ce664…

MALICIOUS

Office (OLE) / .XLSX

1.20 MB
MD5: 48be983e92e7f8b7d6da338994d15fa1 SHA-1: fbec67bc40e50da7fa99f78e6affef79aec4200e SHA-256: e8ef77f22c8ce664462e48e9ef87ff9a2d33bda2d785b454d04e3e5d3eb01c9c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The OOXML file is encrypted with a default password and contains an embedded Equation Editor OLE object. This object exhibits anomalies in its Ole10Native stream, suggesting it is designed to carry a malicious payload. The presence of the Equation Editor OLE object is a strong indicator of an exploit carrier, likely used to deliver a secondary stage.

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.