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

Static analysis result for SHA-256 ea29d81a2564ad39…

MALICIOUS

Office (OLE) / .XLSX

1.04 MB
MD5: b379e19d45da62008667f67e9fcd48bc SHA-1: 383b70d823db6fe7ae00c2b0c1afd234f965cb8c SHA-256: ea29d81a2564ad39f91e61a5124b47927fd3612f69840a39fdf26bb5f923a314
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an OOXML file encrypted with a default password, indicating it's designed to hide its malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object, a known vector for exploiting vulnerabilities. This object appears to carry a payload within its Ole10Native stream, suggesting it's intended to execute arbitrary 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.