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

Static analysis result for SHA-256 f9c1645e9c3555dd…

MALICIOUS

Office (OLE) / .XLSX

1.38 MB
MD5: 69e585e233e8964485cc7ed1cfe7ee27 SHA-1: 81e4433356ad919c382c7cdaf7fb29b4b3a46d14 SHA-256: f9c1645e9c3555ddba0c1fcf5a91ab48b2bd53e68b1c59ddd5bfb33da63d6716
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1559.001 Component Object Model Hijacking

The sample is an encrypted OOXML file that contains an Equation Editor OLE object. This object carries a payload-like Ole10Native stream, indicating it's likely used to exploit a vulnerability, such as CVE-2017-11882, to execute a secondary payload. No document body text or scripts were extracted, making it difficult to determine the exact nature of the payload or its ultimate goal.

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.