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

Static analysis result for SHA-256 c6f578a2a266fee9…

MALICIOUS

Office (OLE) / .XLSX

1.33 MB
MD5: 04a4ee0893001752c65cd252d0887e8d SHA-1: b54d4c14ed3573d90fd0363be9d1a3b50746d87f SHA-256: c6f578a2a266fee9d1656730cb58e152549318981636b2c7b22028fda00bd0b5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file is an OOXML document that is encrypted with a default password, indicating it's likely an exploit carrier. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is a known vector for exploiting vulnerabilities. The Equation Editor object contains a payload-like Ole10Native stream, suggesting it's designed to execute malicious code upon opening.

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.