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

Static analysis result for SHA-256 cd7ed41b0bad9601…

MALICIOUS

Office (OLE) / .XLSX

186.2 KB
MD5: 2c0b4c3de2fcf51b7d7112b911a64593 SHA-1: 7e614c7e634d095af2dc5cb8e98ea169f2b85498 SHA-256: cd7ed41b0bad9601b5697bf4a809d7d6972b47300684760e26cc337014975938
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1203 Exploitation for Client Execution

The sample is a password-encrypted Excel file that contains an embedded Equation Editor OLE object. This combination of heuristics strongly suggests it is an exploit carrier designed to leverage a known vulnerability within the Equation Editor component. The encryption and malformed structure further indicate an attempt to evade static analysis and deliver a malicious payload.

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.