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

Static analysis result for SHA-256 c1bcfa7a9c76bdd8…

MALICIOUS

Office (OLE) / .XLSX

93.5 KB First seen: 2022-04-28
MD5: 7e19e79a5fa3300a7f4e2105bf67dfda SHA-1: 8c59663e512dbd3eb8561e794da215c11d9985df SHA-256: c1bcfa7a9c76bdd830fa265b57e4ede0bbc6e40630c5c52b70b61bcec8492598
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.001 Malicious Link: Malicious File T1059 Command and Scripting Interpreter

This XLSX file is password-encrypted and contains an Equation Editor OLE object. High-confidence heuristics indicate it is an exploit carrier for CVE-2018-0798, a vulnerability affecting Microsoft Equation Editor. The document likely attempts to exploit this vulnerability to execute 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)).
  • 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.