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

Static analysis result for SHA-256 0dbc77ef0568b959…

MALICIOUS

Office (OLE) / .XLSX

178.3 KB
MD5: 3c5e466093cfa44a8b5d332497b64ba8 SHA-1: 2e554dc4ecc95d85b78c850965cbce303d325efe SHA-256: 0dbc77ef0568b95963bbd2de1815df720394723067d76e9a0fd9f76fe4f60c7a
180 Risk Score

Malware Insights

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

The file is a password-encrypted Office document containing an embedded Equation Editor OLE object, a known exploit carrier. The encryption and malformed structure indicate an attempt to hide malicious content, likely an exploit targeting Equation Editor. This pattern is commonly used to deliver secondary payloads via spearphishing attachments.

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.