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

Static analysis result for SHA-256 3920582437338468…

MALICIOUS

Office (OLE) / .XLSX

52.0 KB First seen: 2022-06-16
MD5: e2529fff6ce36ad80157e3a2463ae486 SHA-1: 62cf9812816b28e319f4c2eec5e2bbee09f997c4 SHA-256: 3920582437338468b32c966cd0b9037ad63078d3ed59f4ba749da3076488a85b
120 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is a password-encrypted Office document, a common technique for obfuscating malicious content. High-severity heuristics indicate the presence of an Equation Editor OLE object within an encrypted OOXML exploit carrier, strongly suggesting it's designed to exploit a vulnerability. The encryption and the specific OLE object point towards a delivery mechanism for a secondary payload.

Heuristics 4

  • 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.
  • 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.