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

Static analysis result for SHA-256 74391c9caa3a51dd…

MALICIOUS

Office (OLE) / .XLSX

656.5 KB
MD5: 86e02a80d7cb3251dfbd1b2ff14a94ca SHA-1: 3d97c3fbeb9e5ab11393454852f2b400cd8447c4 SHA-256: 74391c9caa3a51ddd617625c70aa159fd63dedadd20965da79768bbe4bec31c7
120 Risk Score

Malware Insights

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

The sample is an encrypted Office document containing an OLE object that leverages the Equation Editor vulnerability. This technique is commonly used to deliver a malicious payload, likely through a spearphishing attachment, leading to arbitrary code execution on the victim's machine.

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.