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

Static analysis result for SHA-256 ea94d60a4b2c5cda…

MALICIOUS

Office (OLE) / .XLSX

197.0 KB
MD5: 065b639cbf5b21ec79a0bc1b2c9fa763 SHA-1: 29e75084022cec5c184c6793a739b13ba24e0a70 SHA-256: ea94d60a4b2c5cda0cbab3c8736375c9aecb5c884bc248aa93dfa2231e08cdb8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted XLSX file containing an embedded OLE object that leverages a known vulnerability in the Equation Editor (CVE-2018-0798). This indicates the file is designed to exploit this vulnerability for initial execution, likely leading to the download and execution of a second-stage payload. No specific family could be identified, but the exploitation vector is clear.

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.