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

Static analysis result for SHA-256 c9c112cbdcc56d65…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-05-02
MD5: a67636a74b0bf7cbbbc2e0462a58d94e SHA-1: e0205038cb8d4348997a9dcef7d5a9ea2f23307e SHA-256: c9c112cbdcc56d651c2ae88d9df2c11dc948dcafab83b6b6aa4d0a07cf1d6806
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious Link T1559 Component Object Model Hijacking T1559.001 Component Object Model Hijacking: Component Object Model Hijacking T1059 Command and Scripting Interpreter T1059.001 Command and Scripting Interpreter: PowerShell

The file is an encrypted Office document containing an Equation Editor OLE object, which is indicative of exploitation for CVE-2018-0798. This vulnerability allows for the execution of arbitrary code when the document is opened. The presence of multiple OLE object streams suggests a complex exploit carrier designed 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.