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

Static analysis result for SHA-256 86f59f40f378187f…

MALICIOUS

Office (OLE) / .XLSX

101.0 KB First seen: 2022-08-26
MD5: 5163f4176906872d52951a42521f6705 SHA-1: 7712214fc0b57ed53f21ad0705cf52f4983d0187 SHA-256: 86f59f40f378187f9c13ea255db2be54e1833f53e43528562e77b877c1509122
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious File T1059 Command and Scripting Interpreter

The sample is an encrypted Office document, identified as an exploit carrier due to its embedded Equation Editor OLE object. The presence of the 'CVE_2018_0798_EQUATION_NATIVE_ANOMALY' heuristic strongly suggests exploitation of this specific vulnerability. The document's encrypted nature and the use of an OLE object point towards a delivery mechanism for a malicious payload.

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.