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

Static analysis result for SHA-256 a4ee7c0ed6fd9010…

MALICIOUS

Office (OLE) / .XLSX

23.6 KB First seen: 2022-09-16
MD5: 5649bd122cf338cb1c34234f89b43447 SHA-1: 900d61f4ecb2fcd96969458eb31fd64045692601 SHA-256: a4ee7c0ed6fd9010470facf71d8ae193154d93f835596b63ffff87ce834e0cf8
240 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking T1204.002 Malicious File

The sample is a password-encrypted Office document that contains an Equation Editor OLE object, a known exploit carrier. The encryption and malformed structure indicate it is designed to deliver a malicious payload. ClamAV detection further confirms its malicious nature as Doc.Dropper.Agent-6965968-0.

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-6965968-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6965968-0
  • 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.