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

Static analysis result for SHA-256 b2e518ab0c6910f3…

MALICIOUS

Office (OLE) / .XLSX

176.5 KB First seen: 2022-05-19
MD5: 92f06c688108ac69a39f11f5edca349c SHA-1: 564d2b299baf2f2cd21e11595649200c9e46a704 SHA-256: b2e518ab0c6910f3e369ef3c3e3e04a65ced2b438dbdf38323727ae70f5d5728
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1559.001 Component Object Model Hijacking

The sample is an encrypted Office document that contains an Equation Editor OLE object. Heuristics indicate this object is anomalous and specifically flags CVE-2018-0798, suggesting it's designed to exploit this vulnerability. The presence of OLE object streams within the encrypted OOXML further supports its role as an exploit carrier.

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.