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

Static analysis result for SHA-256 96f82c0591792153…

MALICIOUS

Office (OLE) / .XLSX

214.5 KB First seen: 2022-04-26
MD5: 515fe5044943f786aea853ef47029f20 SHA-1: ded9f4bc631aec635d65664c85aca2c92447f5ea SHA-256: 96f82c059179215310e6c86eed03d1dbaaaebfb66c7b57423ba9640d9a2ccc7d
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is a password-encrypted Office document containing an Equation Editor OLE object. High-severity heuristics indicate this object is an exploit carrier for CVE-2018-0798, leveraging an anomalous native stream within the Equation Editor object to achieve code execution. No document body or script content was extractable due to encryption, but the presence of the exploit carrier strongly suggests a malicious intent to compromise the user's system.

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.