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

Static analysis result for SHA-256 806a09e7cfb0c008…

MALICIOUS

Office (OLE) / .XLSX

79.5 KB First seen: 2022-06-20
MD5: 66b47523929b651e5328136d5b84312b SHA-1: bd9eb9e5f2ccffe4a447ef7cdd344b30a92fde27 SHA-256: 806a09e7cfb0c0081ad0782df3f7dd803e46db1bef818e261aa293c2ebb87fbc
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model and Distributed Component Object Model: Component Object Model

The file is a password-encrypted Office document containing an Equation Editor OLE object. Heuristics indicate this object is an exploit carrier, specifically leveraging CVE-2018-0798 due to an anomalous Equation Editor native stream. This suggests the document is designed to exploit a vulnerability in Equation Editor to execute arbitrary code.

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)).
  • 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.