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

Static analysis result for SHA-256 3e820d09da58d55a…

MALICIOUS

Office (OLE) / .XLSX

1.25 MB
MD5: 77767458fa19f75e9fdea10cdd7e4594 SHA-1: 28a8e581dd8aa0980ad5c7ebaa7fa3e8a57f0557 SHA-256: 3e820d09da58d55a29a186169d03d1b5b1d3b895d0e8fe5aa16f7c35d4685c03
140 Risk Score

Malware Insights

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

The sample is an Excel file that is encrypted with a default password, indicating it is likely an exploit carrier. High-severity heuristics indicate the presence of an Equation Editor OLE object, which is a known vector for delivering malicious payloads. The Equation Editor object contains an anomalous Ole10Native stream, suggesting it carries a secondary payload. No scripts were extracted from this sample.

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.
  • 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 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.