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

Static analysis result for SHA-256 a1b81702005bc0c0…

MALICIOUS

Office (OLE) / .XLSX

88.0 KB
MD5: cc8aa2f9ac0a59de457347286fed38f4 SHA-1: e08c061c1616f0c5820b19b0ef48db32deba4a63 SHA-256: a1b81702005bc0c0008777f10049624e5f882c367bac528f82a8895d2a3f1b29
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an OOXML Excel spreadsheet that is password-encrypted using a default password. Heuristics indicate it contains an Equation Editor OLE object, a known carrier for exploits. This suggests the file is designed to exploit a vulnerability, likely via a malicious attachment, to deliver a secondary payload.

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.