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

Static analysis result for SHA-256 99009b2d132f8a2c…

MALICIOUS

Office (OLE) / .XLSX

1.24 MB
MD5: e52fcb60efbd543d51966dde81409abe SHA-1: f7ce816e1d5757eb9bb239ba9ababdec5e8ba173 SHA-256: 99009b2d132f8a2c1d47a690836b514cf32d28095f6158c53a962fe98aaf4c78
140 Risk Score

Malware Insights

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

The sample is an encrypted OOXML file that contains an embedded Equation Editor OLE object. This is a common technique for delivering malicious payloads, often exploiting vulnerabilities within the Equation Editor. The high-severity heuristics indicate that this object is likely carrying a payload, although no specific details about the payload or its delivery mechanism could be extracted from the provided evidence.

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.