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

Static analysis result for SHA-256 cce20e15d25dff33…

MALICIOUS

Office (OLE) / .XLSX

964.0 KB
MD5: 04bc6764f8cdffb64457c5d2a4fb724e SHA-1: 0f07900befe2912a1539b02bf0897c858da65238 SHA-256: cce20e15d25dff33fc03049e3fdfdf643eb50726e55e8c17994f64aa45bcd29e
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file identified as an exploit carrier due to the presence of an Equation Editor OLE object. This object contains an anomalous Ole10Native stream, suggesting it's designed to deliver a malicious payload. The encryption with a default password further indicates an attempt to obscure the malicious content.

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.