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

Static analysis result for SHA-256 4321eb2a1c44ba4e…

MALICIOUS

Office (OLE) / .XLSX

1.21 MB
MD5: ed443ba1d206ab7e14d41a3b3dd377b5 SHA-1: 62efbf426f5b6bd2d1dcdb0f6f5cba3cd3378aba SHA-256: 4321eb2a1c44ba4eb2c486fc75f8e6146b7cf54ed117585867e50869d8ece98c
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 object exhibits anomalies in its Ole10Native stream, suggesting it is designed to carry a malicious payload. The presence of the Equation Editor OLE object is a strong indicator of exploit delivery, often used in conjunction with spearphishing attachments.

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.