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

Static analysis result for SHA-256 76ef311cf44af9a8…

MALICIOUS

Office (OLE) / .XLSX

237.0 KB First seen: 2022-07-15
MD5: f1bb95a9903e15df58fa1782aad670a7 SHA-1: 588ed2480dcb3a63170770dcdf621c58c3d691b5 SHA-256: 76ef311cf44af9a87490da09fe5bc2249908d4e5b348e24d22b93f5a822005ca
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an encrypted Office document identified as an exploit carrier. High-severity heuristics indicate the presence of an Equation Editor OLE object with anomalies consistent with CVE-2018-0798, suggesting it's designed to exploit this vulnerability. No document body or scripts were extractable due to encryption, but the exploit carrier nature is clear.

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.