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

Static analysis result for SHA-256 4149e0673efb023a…

MALICIOUS

Office (OLE) / .XLSX

537.6 KB
MD5: c7ceb25a9ab3e3ed8273f6fc0b4148db SHA-1: 2723bc4ad0bcb5efe248e53ecc06f0cfb903bebd SHA-256: 4149e0673efb023acbbbaf85dc28ce0165d5f097f8d31f801cfd199795c6f8e6
200 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The file is an Office document containing an embedded Equation Editor OLE object, which is a known carrier for exploits like CVE-2018-0798. The ClamAV detection indicates it functions as a downloader. The document body is unreadable, suggesting the malicious content is within the embedded object, likely to execute a secondary payload.

Heuristics 5

  • 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.
  • ClamAV: Xls.Downloader.af2fa5c5d0587870-9978799-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.af2fa5c5d0587870-9978799-0
  • 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.