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

Static analysis result for SHA-256 559afda490876db3…

MALICIOUS

Office (OLE) / .XLSX

197.0 KB
MD5: 4a55d90ed057090c59c875aa44f810c4 SHA-1: 9c6f5d5da5becb077c9539f2e8fb1fb0b122cdcb SHA-256: 559afda490876db35346de0e9b48dc3c27dfed237079233d99fb456c6d628d2f
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 containing an embedded Equation Editor OLE object. High-severity heuristics indicate the presence of CVE-2018-0798, a known vulnerability in Equation Editor, suggesting it's used as an exploit carrier. The document's encryption and the nature of the Equation Editor exploit point towards a malicious payload delivery mechanism.

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.