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

Static analysis result for SHA-256 37107bbfc614754b…

MALICIOUS

Office (OLE) / .XLSX

132.0 KB First seen: 2022-04-21
MD5: 25e3ba10f6d30b552e7c1508594a335f SHA-1: 2221886d84732c21d8c65424851dacf6f7de7bdd SHA-256: 37107bbfc614754b99d49e998f2d0c38829192448cdb4954dfde121aff90f59b
160 Risk Score

Malware Insights

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

The file is an encrypted Office document that contains embedded OLE objects, specifically identified as an Equation Editor object. Heuristics indicate this object is anomalous and likely exploits CVE-2018-0798. This suggests the document is designed to leverage a vulnerability in the Equation Editor to execute malicious code, likely leading to the download and execution of a secondary payload.

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.