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

Static analysis result for SHA-256 90068051983050ab…

MALICIOUS

Office (OLE) / .XLSX

224.0 KB First seen: 2022-05-23
MD5: 7b0adcc000a6ded7e0f5903dd38e12d0 SHA-1: 056960a53cf796d262c8d4cb3fdf5b6a6d22da6c SHA-256: 90068051983050abe52a5eb4d2d2fd32c07c2ae6cb8d3e72f779a4216972a379
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is an encrypted Office document that contains an Equation Editor OLE object. Heuristics indicate that this object is anomalous and exploits CVE-2018-0798, a vulnerability in Microsoft Equation Editor. This vulnerability allows for arbitrary code execution when the document is opened. No scripts were extracted, but the presence of the exploit carrier suggests a payload will be executed.

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-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.