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

Static analysis result for SHA-256 ac1b3b89d18ff82a…

MALICIOUS

Office (OLE) / .XLSX

237.0 KB First seen: 2022-07-16
MD5: e31449b66f9638acce2cb3c07fdf02f3 SHA-1: bb9ef327d5f3fe97e7fc3e71a80ccc35cbbcaa9d SHA-256: ac1b3b89d18ff82a2a9db004361b0ae7c8d338846ef15d3eba32564a206d2494
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1059 Command and Scripting Interpreter

The file is a password-encrypted OOXML document identified as an exploit carrier. It contains an Equation Editor OLE object that exhibits anomalies consistent with CVE-2018-0798, indicating it's designed to exploit this vulnerability for initial execution. The encryption and exploit carrier structure strongly suggest a malicious intent to deliver 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.