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

Static analysis result for SHA-256 c7be5fd7aa9a0970…

MALICIOUS

Office (OLE) / .XLSX

228.8 KB
MD5: 703351b63a7793a8a1f45cd3063a7e34 SHA-1: c1e80890b1622cc66f2e386ebeac791e06fa59c6 SHA-256: c7be5fd7aa9a09702650f1f3cc774425767847dc07b30f2ba01f4ae8c89be95b
180 Risk Score

Malware Insights

MITRE ATT&CK
T1559.001 Component Object Model Hijacking

The sample is an encrypted Excel spreadsheet that utilizes a known exploit carrier technique. Specifically, it contains an embedded Equation Editor OLE object, which is frequently used to deliver malicious payloads. The encryption and malformed structure further indicate a deliberate attempt to obfuscate the malicious content.

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.