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

Static analysis result for SHA-256 6f56c9d48b625862…

MALICIOUS

Office (OLE) / .XLSX

317.5 KB
MD5: e9a734f38e9b62e22e60e1ab5b9f9d6b SHA-1: e979cb5fb91f45cdfb6c638b2fe47a185faf2729 SHA-256: 6f56c9d48b625862bf0ad3bad1ce9521da8e88c53741e4a7bde3c5982120139e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is an encrypted Office document containing an embedded Equation Editor OLE object. Heuristics indicate this object is anomalous and likely exploits CVE-2018-0798, a vulnerability in Equation Editor that allows for arbitrary code execution. The document is likely delivered via spearphishing, and the exploitation of the Equation Editor is the primary mechanism for achieving code execution.

Heuristics 5

  • 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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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.
  • Office document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.