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

Static analysis result for SHA-256 ae6b05fc2658c054…

MALICIOUS

Office (OLE) / .XLSX

1.22 MB
MD5: 7a4fb2d20624b0269cc1b6e59d42c62c SHA-1: 693df75e013dd7ab9d25eb1b4cb2960d8f29a718 SHA-256: ae6b05fc2658c054235f1c1ec677b11da414b67b21e91d64e61f026bfe97d035
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 exploits, as the Equation Editor is a frequent target for vulnerabilities. The presence of an 'Ole10Native' stream within the Equation Editor object, with an anomalous size and header, further suggests it's being used to carry a malicious payload. No scripts were extracted, and the document body was not available, limiting further analysis of the specific exploit or payload.

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.