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

Static analysis result for SHA-256 0fd0e6e3c12a1743…

MALICIOUS

Office (OLE) / .XLSX

65.7 KB First seen: 2023-07-16
MD5: 1e4994937b2105335f604ea23a3dc03f SHA-1: f85118011fef40df44bbacefdc0437a66222a285 SHA-256: 0fd0e6e3c12a17433d352a73ca41b46743c9d181f5526bf8b640a0dfb1e6b3ba
240 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The sample is a password-encrypted Office document that contains an Equation Editor OLE object, a known carrier for exploits. ClamAV identifies it as Doc.Dropper.Agent-6829414-0, suggesting it functions as a dropper. The encryption and malformed structure indicate an attempt to evade analysis.

Heuristics 6

  • 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.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • ClamAV: Doc.Dropper.Agent-6829414-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6829414-0
  • 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.