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

Static analysis result for SHA-256 50fc307d69a0ff2c…

MALICIOUS

Office (OLE) / .XLSX

326.5 KB
MD5: 750dd99ef3c43c27c8259a6cb6ef653a SHA-1: 90fa615138c1445878fcf4c1421e7a88f3c576f0 SHA-256: 50fc307d69a0ff2c322d9911e20a5b4e665bb41e62de53e07d891e1373c18e1a
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 that contains an embedded Equation Editor OLE object. Heuristics indicate that this object is anomalous and exploits CVE-2018-0798, a known vulnerability in Equation Editor. This suggests the document is designed to exploit this vulnerability for initial 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.