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

Static analysis result for SHA-256 257645cd8e215cd4…

MALICIOUS

Office (OLE) / .XLSX

1.18 MB
MD5: c8e623590aae92259642c8c80f761493 SHA-1: 877da933e035b90f881d2c7ef3fa37f9065b6aa7 SHA-256: 257645cd8e215cd4f9c2c153f3605e7389a2aed04a870a1aa0b4a4d9aa5762b3
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1559.001 Component Object Model

The file is an encrypted OOXML document identified as an exploit carrier. It contains multiple embedded OLE objects, with a high-confidence detection of an Equation Editor OLE object that carries a payload-like Ole10Native stream. This strongly suggests the file is designed to exploit the Equation Editor vulnerability (CVE-2017-11882) to deliver a secondary malicious 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.