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

Static analysis result for SHA-256 dabfc6491b528f58…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: f919c9ba5f6609a1d8ce48dd13eba7b4 SHA-1: 8a8a0307f08e18501f155694df01425ea6150163 SHA-256: dabfc6491b528f58a57fbb31b454152063870a3b26609a1b14b496e25b0fb35c
160 Risk Score

Malware Insights

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

The file is a password-encrypted Office document that contains an embedded Equation Editor OLE object. This object exhibits anomalies suggesting it carries a payload, and the presence of the Equation Editor OLE object is a strong indicator of exploitation for client execution. The encryption and the nature of the embedded object point towards a malicious document designed to exploit a vulnerability.

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.
  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • 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.