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

Static analysis result for SHA-256 78a58253b33bfd1e…

MALICIOUS

Office (OLE) / .XLSX

197.0 KB
MD5: b3649a8e594d80a7dafd659247d59d77 SHA-1: effdca13a654d1d50d646db753c2c7c01f787f2e SHA-256: 78a58253b33bfd1e2e6a772e8aa9aafd5497a03f0677430c66442ca35bfa229f
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an encrypted XLSX file containing an embedded Equation Editor OLE object, a known exploit carrier. This suggests the file is designed to exploit a vulnerability within the Equation Editor to execute arbitrary code. The document is encrypted, preventing direct analysis of its content, but the presence of the OLE object strongly indicates an exploitation attempt.

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-128)).
  • 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.