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

Static analysis result for SHA-256 bff3f4183461c7e7…

MALICIOUS

Office (OLE) / .XLSX

421.5 KB
MD5: 34f338cf2d8f95f30cdd94edd67f25d1 SHA-1: 1a71e65558080dcf279966f80d1c794ee3f40b03 SHA-256: bff3f4183461c7e76493d52fe1468e146b65bcb1eb5dc80e1a84513f280fbc62
140 Risk Score

Malware Insights

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

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