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

Static analysis result for SHA-256 9bc3de672afc3a4b…

MALICIOUS

Office (OLE) / .XLSX

197.0 KB
MD5: e3ba2433cfb2aa7850d22cb9a7b2e12d SHA-1: ef5a8c48df92941ea552ae40eb3e0e9e52d1110a SHA-256: 9bc3de672afc3a4bb447af34321ed4ca5e7c9fdab6773d70ca30ed83f7f35b7f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted OOXML file containing an embedded Equation Editor OLE object. Heuristics indicate a high likelihood of exploitation targeting CVE-2018-0798 via anomalous Equation Editor native stream data. This suggests the file is designed to execute arbitrary code upon opening, likely to download and run a secondary payload.

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.