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

Static analysis result for SHA-256 9bfe32f64821b6d6…

MALICIOUS

Office (OLE) / .XLSX

255.9 KB First seen: 2022-06-14
MD5: 0268ca4a9b2949f687f8a66531fe8b21 SHA-1: a1a906aa6f2c49b5e2626b1c7e1819c4ff2f6d85 SHA-256: 9bfe32f64821b6d63f4e07bc6bca0e64bc1afd9fe33bae2ade5291c43486bdeb
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious File T1559.001 Component Object Model Hijacking

The sample is an encrypted XLSX file identified as a malicious exploit carrier. It contains an Equation Editor OLE object, a known vector for exploiting vulnerabilities. The encryption and malformed structure suggest an attempt to obfuscate malicious content, likely leading to the execution of a secondary 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.