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

Static analysis result for SHA-256 3b2b948053944b0e…

MALICIOUS

Office (OLE) / .XLSX

1.16 MB
MD5: cb71c64cc05527c5d4680d005574e77c SHA-1: e6aa264d0964c0c0b39a89c48588ba0abe54058b SHA-256: 3b2b948053944b0eadbfafa1dc127287daa7f76602afc2f8746ead9a483e4302
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains embedded OLE objects, specifically identified as an Equation Editor exploit carrier. The presence of an Equation Editor OLE object with a payload-like Ole10Native stream strongly suggests exploitation of a vulnerability within the Equation Editor component. This is a common technique for delivering secondary payloads.

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.