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

Static analysis result for SHA-256 20a4ac453abfe856…

MALICIOUS

Office (OLE) / .XLSX

1.18 MB
MD5: 18c6b0615e726273e62de9874eaf4ba7 SHA-1: bde398424b87ab3e9944abb2e0eb08be801ddd45 SHA-256: 20a4ac453abfe8568da936d5b736a08e9112667329cd13779e32b7088d2bedef
160 Risk Score

Malware Insights

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

The sample is an encrypted Office XLSX file. High-severity heuristics indicate it contains an Equation Editor OLE object which is a known carrier for exploits. The 'OLE_EQUATION_OLE10NATIVE_PAYLOAD_ANOMALY' heuristic suggests this object contains a payload. The encryption and the presence of embedded OLE objects point towards a malicious document designed to exploit vulnerabilities upon opening.

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.