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

Static analysis result for SHA-256 c3d91e6107b188a2…

MALICIOUS

Office (OLE) / .XLSX

1.31 MB
MD5: 50f48389756e93bd3674004caf2f7aef SHA-1: ebb485de5479bae5a10874e9ef59d0761bd9a408 SHA-256: c3d91e6107b188a28ccae2c7a483f4bcaeec323ee76b181e8db6cadce424c442
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 is known to be used as an exploit carrier, specifically targeting vulnerabilities within the Equation Editor component. The high-entropy Ole10Native stream within the Equation Editor object suggests it contains a secondary payload. The file is likely designed to execute arbitrary code upon opening by exploiting this vulnerability.

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.