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

Static analysis result for SHA-256 50c2c26fd15bb747…

MALICIOUS

Office (OLE) / .XLSX

1.99 MB
MD5: 75d4dec69e2450b610b2587d07fe62cc SHA-1: 8befff244e7404e016137613d4067b4dced7fa05 SHA-256: 50c2c26fd15bb7475368d3847bacfd189a29a57a94815cdee5547a1c34a82f9e
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link

The sample is an encrypted Office document that contains an Equation Editor OLE object. Heuristics indicate that this object is anomalous and likely carries a payload, exploiting CVE-2018-0798. The encryption with a default password further suggests malicious intent. Since no document body or scripts were extracted, the exact payload delivery mechanism beyond the exploit is not discernible.

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.