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

Static analysis result for SHA-256 bd7c85d56fe72222…

MALICIOUS

Office (OLE) / .XLSX

2.13 MB
MD5: 7c87ef46e0285586d13ae8c4837b43b2 SHA-1: 34e125247aee2ff663f7fcae715dc87dc08f8ee9 SHA-256: bd7c85d56fe722221c6b0d7e0c2c37e912f7b16a85dfd2d159c426b99e726ddd
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing T1059 Command and Scripting Interpreter

The sample is an encrypted Office document that contains an Equation Editor OLE object. Heuristics indicate this object is anomalous and likely carries a payload, exploiting CVE-2018-0798. The default encryption password suggests a common, unsophisticated delivery method. The exact payload and delivery mechanism beyond the initial exploit are not discernible from the provided evidence.

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.
  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • 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.