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

Static analysis result for SHA-256 d1acb6e707a46a4d…

MALICIOUS

Office (OLE) / .XLSX

1.18 MB
MD5: 93482300a84e9e96bc62919af9d4c5bd SHA-1: 8ce6f70ea019b39e20dddd6ad2ca04371f444326 SHA-256: d1acb6e707a46a4dab43f72dc39bfe5e34866d9db34238a3e5954ba276cfc4a7
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 Equation Editor OLE object. This object is a known exploit carrier, often used to deliver malicious payloads. The high entropy and size anomaly within the Ole10Native stream suggest it contains embedded malicious content. The default encryption password further indicates a deliberate attempt to obscure the malicious nature of the file.

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.