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

Static analysis result for SHA-256 fe7c82072a63871a…

MALICIOUS

Office (OLE) / .XLSX

1.19 MB
MD5: 2198eb4be81cdb951b359b5925cea125 SHA-1: 89ad3f9d53676851fdb8cbd68a5b600fb7f8761a SHA-256: fe7c82072a63871ab5a3552630c35fcc209c51db1f613f8f4d4ff8574453f1da
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment T1204.001 Malicious Link

The sample is an encrypted Excel file that contains embedded OLE objects. High-severity heuristics indicate that one of these objects is an Equation Editor object which carries a payload-like Ole10Native stream. This strongly suggests the file is designed to exploit the Equation Editor vulnerability to execute a secondary payload. No VBA or scripts were extracted, and no document body was available for analysis.

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.
  • 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.