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

Static analysis result for SHA-256 96d0811b52661931…

MALICIOUS

Office (OLE) / .XLSX

1.31 MB
MD5: 10b98f0ba9d035865d3cd513417a92c6 SHA-1: 8b1935c8b2b501d229366c9d63588b17b9785cda SHA-256: 96d0811b5266193176882515669140eca93225f36654f09fadb760a66a66f8d4
140 Risk Score

Malware Insights

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

The sample is an OOXML file 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, a known vector for delivering exploits. The OLE object contains an anomalous Ole10Native stream, suggesting it carries a payload. No specific family could be identified, but the attack pattern is consistent with exploiting the Equation Editor 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.