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

Static analysis result for SHA-256 b4a70f1bcd573626…

MALICIOUS

Office (OLE) / .XLSX

546.0 KB
MD5: 790b9fcad06c77bfa038f3ab64d7c023 SHA-1: a15ab143a62b7adda825597fec85c5fde7580cdf SHA-256: b4a70f1bcd573626a12fb383ebf12042189634b968f321f13f6e61a0c32416fc
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an encrypted OOXML file containing an Equation Editor OLE object, which is a known exploit carrier. Specifically, the 'CVE_2018_0798_EQUATION_NATIVE_ANOMALY' heuristic indicates exploitation of CVE-2018-0798. The encrypted nature and the presence of an exploit carrier strongly suggest the file is designed to execute arbitrary code upon opening, likely to download and run a second-stage 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.