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

Static analysis result for SHA-256 9d7de8673272f1ee…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: 4c3e622be47c11b82e2cb36784a47ed0 SHA-1: 30163fa5cdf672145190bb140c28d9603ee0d2b1 SHA-256: 9d7de8673272f1ee6aa2597122e733fdb4824edd49c87ddb0b3fa792674f33e6
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains an Equation Editor OLE object. This object appears to carry a payload within its Ole10Native stream, indicating an attempt to exploit vulnerabilities within the Equation Editor component for initial execution. The specific nature of the payload is not discernible from static analysis alone.

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.