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

Static analysis result for SHA-256 1fd25d3d4191616e…

MALICIOUS

Office (OLE) / .XLSX

181.0 KB First seen: 2022-06-16
MD5: 03e777a053561a6dbacbd4cb6bb5f2ad SHA-1: 607c4e637cf8efec5bb12905804d2602887bbdf6 SHA-256: 1fd25d3d4191616e942a7c6c645a2ff19e19246eee863eabaae4b4b67137f87c
160 Risk Score

Malware Insights

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

The sample is a password-encrypted OOXML file that contains embedded OLE objects, specifically identified as an Equation Editor object. High-confidence heuristics indicate this object is anomalous and exploits CVE-2018-0798. This suggests the document is designed as an exploit carrier, leveraging the Equation Editor vulnerability to execute a secondary payload. No document body text was 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)).
  • 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.