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

Static analysis result for SHA-256 258c9b6c08b54bbe…

MALICIOUS

Office (OLE) / .XLSX

2.56 MB
MD5: 530925a4c1000f24d318a748c6a2fc20 SHA-1: 8b1d0ca5f5fb9a26bd0b0954f30a2b93da893764 SHA-256: 258c9b6c08b54bbe1eed3bbb3454271f1ec42419c05c3b0909f31d48268bf13c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The OOXML file is encrypted with a default password and contains an embedded Equation Editor OLE object. This object exhibits anomalies in its Ole10Native stream, suggesting it's designed to carry a malicious payload. The presence of the Equation Editor OLE object is a strong indicator of exploit delivery, likely via a spearphishing attachment.

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.