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

Static analysis result for SHA-256 f7b65ad97f2147fa…

MALICIOUS

Office (OLE) / .XLSX

184.5 KB First seen: 2022-05-12
MD5: c99168b461c218e82e81121fa82c418e SHA-1: 2c895f4cecc6ee9d44a72d66db97c10c51eee148 SHA-256: f7b65ad97f2147fa1b43ba70d5baac0f9b3a0a1c472f0ba923fc5421ddff65e2
160 Risk Score

Malware Insights

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

The sample is an encrypted Office XLSX file. Heuristics indicate it is an exploit carrier leveraging an Equation Editor OLE object, specifically triggering an anomaly associated with CVE-2018-0798. This suggests the document is designed to exploit this vulnerability upon opening, likely leading to the execution of a secondary payload. No document body or scripts were extractable due to encryption.

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-128)).
  • 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.