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

Static analysis result for SHA-256 4eaaa7dc03cc461a…

MALICIOUS

Office (OLE) / .XLSX

224.0 KB First seen: 2022-05-20
MD5: 71336e3b7838ef9eeee9f819f398463c SHA-1: 9cf294e9d1fa8c33591130731022608307ddbd4b SHA-256: 4eaaa7dc03cc461a9cfc0bbf593203dbb011b161bb5108e889dbe5c9b906888d
160 Risk Score

Malware Insights

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

The sample is an encrypted Office document containing an Equation Editor OLE object, which is a known carrier for exploits. Specifically, the 'CVE_2018_0798_EQUATION_NATIVE_ANOMALY' heuristic indicates exploitation of CVE-2018-0798. The document's encrypted nature and the presence of exploit-related OLE objects suggest it is designed to deliver a malicious 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.