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

Static analysis result for SHA-256 0063fb81e8d62c56…

MALICIOUS

Office (OLE) / .XLSX

284.2 KB First seen: 2022-07-11
MD5: 307a1e70cddfc7bebaa6cddc265d2b9c SHA-1: d8184489ffd09beaa7be4d69f8f1b425fc09d863 SHA-256: 0063fb81e8d62c56fa0a91c51be2fc3550de5bba04d6b2a26c65f25ae9aa52fe
220 Risk Score

Malware Insights

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

The sample is an encrypted Office document that contains an embedded Equation Editor OLE object. Heuristics indicate this object is anomalous and likely exploits CVE-2018-0798, a vulnerability related to the Equation Editor. The document's encryption and malformed structure suggest it's designed to act as a carrier for a malicious payload, likely executed upon user interaction.

Heuristics 6

  • 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.
  • Encrypted Office package with CFB FAT corruption critical OLE_ENCRYPTED_AND_MALFORMED
    Encrypted-package shape co-occurs with FAT-chain corruption — the documented combined evasion form.
  • 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.