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

Static analysis result for SHA-256 8192e8fe2ad2e672…

MALICIOUS

Office (OLE) / .XLSX

360.4 KB
MD5: de032c878b20d9a9c94e278033fca748 SHA-1: 200fe4158ad6c392922f10f5a6af5707969f6b57 SHA-256: 8192e8fe2ad2e67232d6c99fabb9bb32ecba8606796ac88b30e9b7c112880ec5
180 Risk Score

Malware Insights

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

The sample is a password-encrypted OOXML file identified as an exploit carrier. It contains an Equation Editor OLE object, a common vector for exploiting vulnerabilities like CVE-2017-11882. The encryption and malformed structure indicate an attempt to obfuscate malicious content, likely delivered via spearphishing.

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.