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

Static analysis result for SHA-256 07a12c478721a693…

MALICIOUS

Office (OLE) / .XLSX

1.15 MB
MD5: 2802f5f2dea1a3d03cdb374ef0e2be9b SHA-1: ef1aa92aa5fe4f286acbf92869a966262388bf9b SHA-256: 07a12c478721a693d8f8b7b6cc750a2735b72f1c6666f70d9187842408966b5c
160 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The file is an encrypted OOXML document identified as an exploit carrier due to the presence of embedded OLE objects, specifically an Equation Editor object. This object contains an anomalous Ole10Native stream, strongly suggesting it is designed to exploit a vulnerability for client execution. The document's encrypted nature and the embedded exploit object indicate it was likely delivered as a spearphishing attachment.

Heuristics 5

  • 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 document is password-encrypted medium OFFICE_ENCRYPTED_PACKAGE
    OLE container holds MS-OFFCRYPTO encrypted package (Standard Encryption (Office 2007+, AES-128)).
  • 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.