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

Static analysis result for SHA-256 04e5b3fccfe7a2bc…

MALICIOUS

Office (OLE) / .XLSX

2.34 MB
MD5: 98864c7012f43312b6b205c06f804a4d SHA-1: 10f690b3420298a16ddebb9e41067b29bd7bffc2 SHA-256: 04e5b3fccfe7a2bce70605e5a7009117d717a1fbae3e38cbd4e1de64d790d0a0
200 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is an encrypted Office document containing an embedded Equation Editor OLE object. Heuristics indicate this object is anomalous and likely carries a malicious payload, exploiting CVE-2018-0798. The encrypted nature of the document prevents further analysis of its direct content, but the presence of the exploit carrier is a strong indicator of malicious intent.

Heuristics 6

  • 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 document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.