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

Static analysis result for SHA-256 1e2f9c18c7dd61c7…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: 8fe0e58e5a1325f9f63f0ab116f33ff3 SHA-1: 7e9f361b395d48b93f0b5d1baf9018741dc6fb4e SHA-256: 1e2f9c18c7dd61c7acdf6fbc136fccbd7a2f408577373e8892925601e4c689e8
140 Risk Score

Malware Insights

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

The sample is an OOXML file encrypted with a default password, indicating it's likely an exploit carrier. High-severity heuristics identify an Equation Editor OLE object containing a payload-like stream, suggesting exploitation of a vulnerability within the Equation Editor. This points to a delivery mechanism for a malicious payload, likely via a spearphishing attachment.

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.