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

Static analysis result for SHA-256 bee546e0799cf2da…

MALICIOUS

Office (OLE) / .XLSX

132.5 KB First seen: 2022-04-21
MD5: 8d44898deb807658c87b5ad331bc0c46 SHA-1: 9d2566f1dd010f5144632e9cb3086c17497d6fae SHA-256: bee546e0799cf2da750157adffe92da73a9503311ae0f90490df24046c330e37
160 Risk Score

Malware Insights

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

The file is an encrypted Office document containing an Equation Editor OLE object. High-severity heuristics indicate this object is an exploit carrier for CVE-2018-0798, a vulnerability in Equation Editor. The encrypted nature and the presence of multiple OLE object streams suggest the document is designed to exploit this vulnerability upon opening, likely leading to the 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.