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

Static analysis result for SHA-256 a5d925e5395da164…

MALICIOUS

Office (OLE) / .XLSX

1.32 MB
MD5: f47c800c0a67f052995726b168874f27 SHA-1: 638829f0b340511af6d2ac07d20dff6474a4d489 SHA-256: a5d925e5395da164cd9be65382ce904b7c0b99d6c93b476697c7dcc1f9989e87
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 Malicious Link

The file is an encrypted OOXML document identified as an exploit carrier. It contains an Equation Editor OLE object, a common technique for delivering malicious payloads. The presence of an 'Ole10Native' stream anomaly within the Equation Editor object suggests it is designed to execute arbitrary code. The default encryption password further indicates a lack of legitimate user interaction.

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.