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

Static analysis result for SHA-256 f2762acdc3244d8a…

MALICIOUS

Office (OLE) / .XLSX

868.5 KB
MD5: 1ab240bbf7af46eb1b768bcccf9047e0 SHA-1: 6cc956fa8d830fd6133f5cd9fb23f49f1667e998 SHA-256: f2762acdc3244d8adb11c318ac93b1ef63db750245a5f77e258af676d39e85b4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1559.001 Component Object Model Hijacking

The sample is a default-encrypted OOXML file identified as an exploit carrier. It contains an Equation Editor OLE object which exhibits an anomaly, suggesting it carries a payload. This indicates the file is designed to exploit a vulnerability in the Equation Editor to achieve code execution.

Heuristics 4

  • 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.
  • 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.
  • Equation Editor object carries payload-like Ole10Native stream high OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY
    Default-encrypted OOXML embedded OLE object declares the Equation Editor CLSID but stores a large high-entropy Ole10Native stream with malformed package sizing. This is exploit-shaped Equation/OLE payload evidence.
  • 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.