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

Static analysis result for SHA-256 8f10aa9111619186…

MALICIOUS

Office (OLE) / .XLSX

1.06 MB
MD5: 310ec830e8ba65617534703d4c09d408 SHA-1: f20443c61751b615c93874c72e34d826a5c11c5c SHA-256: 8f10aa911161918639a14e7ca3fb0df0c6f641bb937f9bcb38a99a80400e6f77
140 Risk Score

Malware Insights

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

The file is an encrypted OOXML document that utilizes a default password, a common technique for obfuscating malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is frequently used to deliver exploits. The OLE object contains an anomalous Ole10Native stream, suggesting it carries a payload. No document body or scripts were extractable due to encryption.

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.