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

Static analysis result for SHA-256 30ea39f0326b125e…

MALICIOUS

Office (OLE) / .XLSX

317.5 KB
MD5: 0bbc19eba9b81408500b3a530e42cbaa SHA-1: f9dff9f81d61268576cf0f3d89fb7b26a442662c SHA-256: 30ea39f0326b125eb1c5f4607f0a4e3af8196f4104ba96ae7219fcaa1688cf20
160 Risk Score

Malware Insights

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

The sample is an encrypted Office document, identified as an exploit carrier due to its embedded Equation Editor OLE object. The presence of the 'CVE_2018_0798_EQUATION_NATIVE_ANOMALY' heuristic strongly suggests exploitation of CVE-2018-0798 via the Equation Editor. This indicates the document is designed to deliver a second-stage payload upon opening.

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.