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

Static analysis result for SHA-256 fadcfd2f990a0f87…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-08-11
MD5: e473032e06ba9f136297d20963106f68 SHA-1: 5cc2bf5d294d7ceccd5e8a1f995e01035ed056ae SHA-256: fadcfd2f990a0f871a1834723d403a0598faf9f06ca75465c58b69d81342c08f
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 containing an embedded Equation Editor OLE object. This object exhibits anomalies consistent with the CVE-2018-0798 Equation Editor vulnerability, indicating it's likely an exploit carrier. The encryption and the specific OLE object suggest an attempt to deliver a malicious payload via exploitation of this known vulnerability.

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.