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

Static analysis result for SHA-256 f7ec78f3f1a9841f…

MALICIOUS

Office (OLE) / .XLSX

592.0 KB
MD5: bf2d3ba7e0577d2a573e54173b98f6fb SHA-1: c78f70929cbf577edc158ddbc3316362a5f0a83f SHA-256: f7ec78f3f1a9841f6fb382af1115ec23f0680783268f6ae48338db6bfdea8a2d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The sample is an encrypted OOXML file identified as an exploit carrier. It contains an Equation Editor OLE object that exhibits anomalies consistent with CVE-2018-0798. This indicates the file is designed to exploit a vulnerability in the Equation Editor component to achieve code execution.

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.
  • CVE-2018-0798 — anomalous Equation Editor native stream high CVE likely CVE_2018_0798_EQUATION_NATIVE_ANOMALY
    Default-encrypted OOXML contains embedded Equation Editor data with anomalous native stream bytes consistent with a CVE-2018-0798-style exploit. This is treated as likely CVE evidence because the Equation object is malformed and payload-like.
  • 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 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.