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

Static analysis result for SHA-256 f7fe5a2576990aa6…

MALICIOUS

Office (OLE) / .XLSX

118.0 KB First seen: 2022-04-27
MD5: 16bdec435ce67b9cdbd98ee99bc2673f SHA-1: aa6a80d312fcdeb712a985487f715457b3558327 SHA-256: f7fe5a2576990aa60543f1f32889b7237618c9b84627112a08a6d9a7a16b2ed8
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is a password-encrypted Office document that contains an Equation Editor OLE object. This object exhibits anomalies consistent with CVE-2018-0798, indicating it's likely an exploit carrier. The primary attack vector is the exploitation of this vulnerability to achieve arbitrary code execution.

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.