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

Static analysis result for SHA-256 f22d458cd78a70c9…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-04-27
MD5: ddec6637bbb302a179bfdf301822c6d7 SHA-1: 863d969aa8fba9ab7887d2d9121891548b8c931f SHA-256: f22d458cd78a70c933f6ff7799cfe30dd4ead966bad157db23de10dce45879e7
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 XLSX document that contains an Equation Editor OLE object. Heuristics indicate this object is an exploit carrier for CVE-2018-0798, a vulnerability in Microsoft Equation Editor. The encrypted nature of the document prevents further analysis of its contents, but the presence of the exploit carrier strongly suggests it's designed to execute arbitrary code upon opening.

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.