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

Static analysis result for SHA-256 383afe14fdd7e01d…

MALICIOUS

Office (OLE) / .XLSX

595.5 KB
MD5: 883eaded344877a84fda4b7f12f1e285 SHA-1: e78ab0c8359073bea3ea575275f45a7450043ee5 SHA-256: 383afe14fdd7e01d4f03dfeecd1fea9f9d9ab50c827ffe71f8006191dd03b39f
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1204.002 Malicious File: User Execution: Malicious Attachment T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model

The sample is a password-encrypted OOXML file that contains an embedded Equation Editor OLE object. High-confidence heuristics indicate this object is designed to exploit CVE-2018-0798. The anomalous native stream within the Equation Editor object suggests it is being used as a carrier for a malicious payload, likely for initial 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.