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

Static analysis result for SHA-256 65ce95d1dd6e75df…

MALICIOUS

Office (OLE) / .XLSX

116.0 KB First seen: 2022-08-30
MD5: aa4cf6eb2982d7e125477d078c169e61 SHA-1: 63ca94f6e65f8f931fb94f16d846af6ce6e4b523 SHA-256: 65ce95d1dd6e75dfe1cf7a1cfef624356bc105e45395ee92f78a0a5401dc94c3
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model T1059 Command and Scripting Interpreter

The file is a password-encrypted Excel spreadsheet containing an embedded Equation Editor OLE object. Heuristics indicate this object is anomalous and specifically targets CVE-2018-0798, a vulnerability in Equation Editor. This suggests the file is designed to exploit this vulnerability when the OLE object is processed, likely leading to arbitrary 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.