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

Static analysis result for SHA-256 7a45581ba55ef948…

MALICIOUS

Office (OLE) / .XLSX

229.1 KB
MD5: 68ed30b7cd06537a15ef902d9975ac91 SHA-1: 31c4f92386f84248e72474ecf334646d3f9aad3c SHA-256: 7a45581ba55ef94807097c8c596f4b6d26f6d85e631d9114adcb85bf05e05937
180 Risk Score

Malware Insights

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

The sample is an encrypted XLSX file that contains an embedded Equation Editor OLE object. This is a known technique for delivering exploits. The document is encrypted with a default password and exhibits malformed structures, indicating it's likely an exploit carrier. No document body or scripts were extractable due to encryption.

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.
  • 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.
  • 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.