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

Static analysis result for SHA-256 97091bd760367302…

MALICIOUS

Office (OLE) / .XLSX

94.0 KB First seen: 2022-04-27
MD5: c36bdde8f040c811a44c5d00b4eb7c9e SHA-1: 1495d4ef450dc63d0dd4659c527e96f7e732c2ca SHA-256: 97091bd7603673029a449ae4ef0bb7bacedd9157bfe0dd6a59d5b1675045e7d1
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The file is an encrypted Office document that contains an Equation Editor OLE object. High-severity heuristics indicate this object is anomalous and exploits CVE-2018-0798. This suggests the document is designed to leverage the Equation Editor vulnerability for arbitrary code execution. No scripts were extracted, and the document body is encrypted, limiting further analysis of the payload.

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.