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

Static analysis result for SHA-256 c9ff1a872a38e415…

MALICIOUS

Office (OLE) / .XLSX

317.0 KB
MD5: d77f00df2b7eb688116d54b2069201b4 SHA-1: ea5f8497c1f619a1f400aa5ef9d7a3fc401ca85a SHA-256: c9ff1a872a38e41598adff4d264706041b5d2ddda74ae6b2f79cadecde755ad5
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The file is a password-encrypted OOXML spreadsheet containing an embedded OLE object, specifically an Equation Editor object. Heuristics indicate this object is anomalous and exploits CVE-2018-0798. This exploit is known to be used as a carrier for malicious payloads. The embedded OLE object is located at xl/embeddings/oleObject1.bin.

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.