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

Static analysis result for SHA-256 c3b442727537d516…

MALICIOUS

Office (OLE) / .XLSX

2.02 MB
MD5: 4c93eed9d3f842f888fb7b3c403ce203 SHA-1: 101420cd223238072d3242e6fd67100d252f62b8 SHA-256: c3b442727537d516f49dc689c3e6cad33e01b1667ac0b7921810eafb8652cd08
180 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566 Phishing

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. Heuristics indicate a high likelihood of exploitation for CVE-2018-0798, a vulnerability affecting Equation Editor. This suggests the file is designed to exploit this vulnerability to execute a malicious payload, likely delivered via the anomalous Ole10Native stream within the OLE object.

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.