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

Static analysis result for SHA-256 c7bf7a6c4655e31f…

MALICIOUS

Office (OLE) / .XLSX

521.8 KB
MD5: 3636377f8a772f02bc3747e9aa7e65b1 SHA-1: 4a56e3c64cafcdd73dc23df5f8566438db4c526f SHA-256: c7bf7a6c4655e31f42bfee020ea2e939274766bc68fe4d52c64a31d116bf1012
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The sample is an OOXML file that is encrypted with a default password and contains embedded OLE objects, specifically identified as Equation Editor objects. High-severity heuristics indicate the presence of an exploit carrier and an anomaly in the Equation Editor's native stream, strongly suggesting exploitation of CVE-2018-0798. This points to a pattern of using a vulnerable component to execute arbitrary code.

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.