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

Static analysis result for SHA-256 f9637d3509f18a48…

MALICIOUS

Office (OLE) / .XLSX

343.5 KB First seen: 2022-04-13
MD5: f12d0a003e9365c8fe3d62bceb782f6b SHA-1: 12cfeb718767f791f30d6892a45ca9e9cf041324 SHA-256: f9637d3509f18a48b9bd29e3a22474c1a0783f5e50b46bdcdbd2d3094e297137
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is an encrypted Office document containing an Equation Editor OLE object. Heuristics indicate exploitation of CVE-2018-0798 via an anomalous Equation Editor native stream, suggesting it acts as an exploit carrier. The specific payload or delivery mechanism beyond the exploit itself is not detailed in the provided evidence.

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