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

Static analysis result for SHA-256 328110532cee3caf…

MALICIOUS

Office (OLE) / .XLSX

991.9 KB
MD5: 904a0059b8d8cb5b54a40601affdd071 SHA-1: 77779b8c03efcfe32649c472da0b1101f62f1fc5 SHA-256: 328110532cee3caf89125d4abb2bb460226e6173c7ccc49e571149533f0c64a0
140 Risk Score

Malware Insights

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

The file is an OOXML document encrypted with a default password, indicating it's likely an exploit carrier. It contains an Equation Editor OLE object, a known vector for delivering malicious payloads via vulnerabilities like CVE-2017-11882. The presence of an anomalous Ole10Native stream within the Equation Editor object strongly suggests it's designed 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.