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

Static analysis result for SHA-256 2509396fd264d5cb…

MALICIOUS

Office (OLE) / .XLSX

343.5 KB First seen: 2022-04-12
MD5: b9be604a1f222d8b4fdf4e11a4bacb5e SHA-1: f1a6fd4102caad1ade4842ef778bff5a1454147d SHA-256: 2509396fd264d5cb19e55d0e0e74f8f32b4ba9ec82a35c0b697566f78df6122e
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059 Command and Scripting Interpreter

The sample is a password-encrypted XLSX file that contains 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 exploit likely leads to the execution of a second-stage payload. No document body or scripts were extractable due to encryption.

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.