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

Static analysis result for SHA-256 9584a27702d6f6fd…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: 1a23b8c8e5fa52a917c92207a8316b55 SHA-1: 7b481fe511b2132d2d2dc7cad79aa5ebda0d3388 SHA-256: 9584a27702d6f6fdecc4589a5c87b529ef2c41ca556ddf9325999a4bdb58fcc3
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1559 Component Object Model Hijacking

The sample is an OOXML file encrypted with a default password, indicating it's likely an exploit carrier. High-severity heuristics indicate the presence of an Equation Editor OLE object (OLE_EQUATION_EDITOR) which contains a payload-like Ole10Native stream (OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY). This strongly suggests the file is designed to exploit a vulnerability within the Equation Editor component to execute a secondary payload.

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.