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

Static analysis result for SHA-256 d764c47245671697…

MALICIOUS

Office (OLE) / .XLSX

1.21 MB
MD5: fd084269903ab4b2354aabb96cf46764 SHA-1: 4f1ebf3cf19d8eb1a53b50bd4eaafff005c628cb SHA-256: d764c472456716972abf910c9568dffe1301cee889b69f5fee31521bbc950255
140 Risk Score

Malware Insights

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

The file is an encrypted Excel spreadsheet that contains an embedded Equation Editor OLE object. This object exhibits anomalies suggesting it carries a payload, likely exploiting a vulnerability within the Equation Editor component. The encryption with a default password further indicates an attempt to obscure malicious content. The presence of the Equation Editor OLE object points towards an exploit carrier.

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.